1551505440 has 96 divisors (see below), whose sum is σ = 4935784896. Its totient is φ = 409625600.

The previous prime is 1551505367. The next prime is 1551505441. The reversal of 1551505440 is 445051551.

1551505440 is digitally balanced in base 6, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (96).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 1551505398 and 1551505407.

It is not an unprimeable number, because it can be changed into a prime (1551505441) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 32479 + ... + 64481.

It is an arithmetic number, because the mean of its divisors is an integer number (51414426).

Almost surely, 2^1551505440 is an apocalyptic number.

1551505440 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1551505440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2467892448).

1551505440 is an abundant number, since it is smaller than the sum of its proper divisors (3384279456).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1551505440 is a wasteful number, since it uses less digits than its factorization.

1551505440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32122 (or 32114 counting only the distinct ones).

The product of its (nonzero) digits is 10000, while the sum is 30.

The square root of 1551505440 is about 39389.1538370654. The cubic root of 1551505440 is about 1157.6690807526.

Adding to 1551505440 its reverse (445051551), we get a palindrome (1996556991).

The spelling of 1551505440 in words is "one billion, five hundred fifty-one million, five hundred five thousand, four hundred forty".