21555515312 has 40 divisors (see below), whose sum is σ = 42072642000. Its totient is φ = 10698159872.

The previous prime is 21555515281. The next prime is 21555515321. The reversal of 21555515312 is 21351555512.

It is a super-3 number, since 3×21555515312³ (a number of 32 digits) contains 333 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5860418 + ... + 5864094.

It is an arithmetic number, because the mean of its divisors is an integer number (1051816050).

Almost surely, 2^21555515312 is an apocalyptic number.

It is an amenable number.

21555515312 is a deficient number, since it is larger than the sum of its proper divisors (20517126688).

21555515312 is a wasteful number, since it uses less digits than its factorization.

21555515312 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6293 (or 6287 counting only the distinct ones).

The product of its digits is 37500, while the sum is 35.

The spelling of 21555515312 in words is "twenty-one billion, five hundred fifty-five million, five hundred fifteen thousand, three hundred twelve".