21251103524 has 12 divisors (see below), whose sum is σ = 42502207104. Its totient is φ = 9107615784.

The previous prime is 21251103493. The next prime is 21251103547. The reversal of 21251103524 is 42530115212.

21251103524 is an admirable number.

It is a junction number, because it is equal to n+sod(n) for n = 21251103493 and 21251103502.

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, 379483964 + ... + 379484019.

It is an arithmetic number, because the mean of its divisors is an integer number (3541850592).

Almost surely, 2^21251103524 is an apocalyptic number.

It is an amenable number.

21251103524 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

21251103524 is a wasteful number, since it uses less digits than its factorization.

21251103524 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 758967994 (or 758967992 counting only the distinct ones).

The product of its (nonzero) digits is 2400, while the sum is 26.

Adding to 21251103524 its reverse (42530115212), we get a palindrome (63781218736).

The spelling of 21251103524 in words is "twenty-one billion, two hundred fifty-one million, one hundred three thousand, five hundred twenty-four".