1551621984 has 96 divisors (see below), whose sum is σ = 4482946944. Its totient is φ = 465991680.

The previous prime is 1551621983. The next prime is 1551621989. The reversal of 1551621984 is 4891261551.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1551621983) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 112827 + ... + 125829.

It is an arithmetic number, because the mean of its divisors is an integer number (46697364).

Almost surely, 2^1551621984 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1551621984, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2241473472).

1551621984 is an abundant number, since it is smaller than the sum of its proper divisors (2931324960).

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

1551621984 is a wasteful number, since it uses less digits than its factorization.

1551621984 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13140 (or 13132 counting only the distinct ones).

The product of its digits is 86400, while the sum is 42.

The square root of 1551621984 is about 39390.6332013082. The cubic root of 1551621984 is about 1157.6980667950.

The spelling of 1551621984 in words is "one billion, five hundred fifty-one million, six hundred twenty-one thousand, nine hundred eighty-four".