21515102100056 has 32 divisors (see below), whose sum is σ = 40396856544000. Its totient is φ = 10742615160480.

The previous prime is 21515102100031. The next prime is 21515102100059. The reversal of 21515102100056 is 65000120151512.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21515102100059) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 20718101 + ... + 21731771.

It is an arithmetic number, because the mean of its divisors is an integer number (1262401767000).

Almost surely, 2^{21515102100056} is an apocalyptic number.

It is an amenable number.

21515102100056 is a deficient number, since it is larger than the sum of its proper divisors (18881754443944).

21515102100056 is a wasteful number, since it uses less digits than its factorization.

21515102100056 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1017359 (or 1017355 counting only the distinct ones).

The product of its (nonzero) digits is 3000, while the sum is 29.

Adding to 21515102100056 its reverse (65000120151512), we get a palindrome (86515222251568).

The spelling of 21515102100056 in words is "twenty-one trillion, five hundred fifteen billion, one hundred two million, one hundred thousand, fifty-six".