1553421440 has 128 divisors (see below), whose sum is σ = 3884094720. Its totient is φ = 593510400.

The previous prime is 1553421433. The next prime is 1553421473. The reversal of 1553421440 is 441243551.

It is a tau number, because it is divible by the number of its divisors (128).

It is a hoax number, since the sum of its digits (29) coincides with the sum of the digits of its distinct prime factors.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1292840 + ... + 1294040.

It is an arithmetic number, because the mean of its divisors is an integer number (30344490).

Almost surely, 2^1553421440 is an apocalyptic number.

1553421440 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 1553421440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1942047360).

1553421440 is an abundant number, since it is smaller than the sum of its proper divisors (2330673280).

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

1553421440 is a wasteful number, since it uses less digits than its factorization.

1553421440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1310 (or 1298 counting only the distinct ones).

The product of its (nonzero) digits is 9600, while the sum is 29.

The square root of 1553421440 is about 39413.4677489814. The cubic root of 1553421440 is about 1158.1454313267.

Adding to 1553421440 its reverse (441243551), we get a palindrome (1994664991).

The spelling of 1553421440 in words is "one billion, five hundred fifty-three million, four hundred twenty-one thousand, four hundred forty".