21251041100056 has 16 divisors (see below), whose sum is σ = 39989549366640. Its totient is φ = 10587161268960.

The previous prime is 21251041100041. The next prime is 21251041100119. The reversal of 21251041100056 is 65000114015212.

It is a junction number, because it is equal to n+sod(n) for n = 21251041099997 and 21251041100033.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4794907780 + ... + 4794912211.

It is an arithmetic number, because the mean of its divisors is an integer number (2499346835415).

Almost surely, 2^{21251041100056} is an apocalyptic number.

It is an amenable number.

21251041100056 is a deficient number, since it is larger than the sum of its proper divisors (18738508266584).

21251041100056 is a wasteful number, since it uses less digits than its factorization.

21251041100056 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9589820274 (or 9589820270 counting only the distinct ones).

The product of its (nonzero) digits is 2400, while the sum is 28.

Adding to 21251041100056 its reverse (65000114015212), we get a palindrome (86251155115268).

The spelling of 21251041100056 in words is "twenty-one trillion, two hundred fifty-one billion, forty-one million, one hundred thousand, fifty-six".