15987289920 has 448 divisors, whose sum is σ = 60399753216. Its totient is φ = 3506872320.

The previous prime is 15987289873. The next prime is 15987289979. The reversal of 15987289920 is 2998278951.

It is a tau number, because it is divible by the number of its divisors (448).

It is a super-2 number, since 2×15987289920² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (60).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 17626107 + ... + 17627013.

Almost surely, 2^15987289920 is an apocalyptic number.

15987289920 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 15987289920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30199876608).

15987289920 is an abundant number, since it is smaller than the sum of its proper divisors (44412463296).

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

15987289920 is a wasteful number, since it uses less digits than its factorization.

15987289920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1038 (or 1028 counting only the distinct ones).

The product of its (nonzero) digits is 6531840, while the sum is 60.

The spelling of 15987289920 in words is "fifteen billion, nine hundred eighty-seven million, two hundred eighty-nine thousand, nine hundred twenty".