15312021312 has 224 divisors, whose sum is σ = 49719951360. Its totient is φ = 4059095040.

The previous prime is 15312021259. The next prime is 15312021331. The reversal of 15312021312 is 21312021351.

It is a tau number, because it is divible by the number of its divisors (224).

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1617489 + ... + 1626927.

Almost surely, 2^15312021312 is an apocalyptic number.

15312021312 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 15312021312, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24859975680).

15312021312 is an abundant number, since it is smaller than the sum of its proper divisors (34407930048).

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

15312021312 is a wasteful number, since it uses less digits than its factorization.

15312021312 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9549 (or 9539 counting only the distinct ones).

The product of its (nonzero) digits is 360, while the sum is 21.

Adding to 15312021312 its reverse (21312021351), we get a palindrome (36624042663).

The spelling of 15312021312 in words is "fifteen billion, three hundred twelve million, twenty-one thousand, three hundred twelve".