21499959312 has 240 divisors, whose sum is σ = 65723793408. Its totient is φ = 6521748480.

The previous prime is 21499959287. The next prime is 21499959317. The reversal of 21499959312 is 21395999412.

21499959312 is a `hidden beast` number, since 2 + 1 + 49 + 9 + 9 + 593 + 1 + 2 = 666.

It is not an unprimeable number, because it can be changed into a prime (21499959317) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 56135473 + ... + 56135855.

Almost surely, 2^21499959312 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 21499959312, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32861896704).

21499959312 is an abundant number, since it is smaller than the sum of its proper divisors (44223834096).

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

21499959312 is a wasteful number, since it uses less digits than its factorization.

21499959312 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 758 (or 749 counting only the distinct ones).

The product of its digits is 1574640, while the sum is 54.

The spelling of 21499959312 in words is "twenty-one billion, four hundred ninety-nine million, nine hundred fifty-nine thousand, three hundred twelve".