15651991512 has 144 divisors (see below), whose sum is σ = 44743626720. Its totient is φ = 4940576640.

The previous prime is 15651991501. The next prime is 15651991571. The reversal of 15651991512 is 21519915651.

It is a super-2 number, since 2×15651991512² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 3249618 + ... + 3254430.

It is an arithmetic number, because the mean of its divisors is an integer number (310719630).

Almost surely, 2^15651991512 is an apocalyptic number.

15651991512 is a gapful number since it is divisible by the number (12) 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 15651991512, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22371813360).

15651991512 is an abundant number, since it is smaller than the sum of its proper divisors (29091635208).

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

15651991512 is a wasteful number, since it uses less digits than its factorization.

15651991512 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4934 (or 4896 counting only the distinct ones).

The product of its digits is 121500, while the sum is 45.

The spelling of 15651991512 in words is "fifteen billion, six hundred fifty-one million, nine hundred ninety-one thousand, five hundred twelve".