21523649250 has 64 divisors (see below), whose sum is σ = 55175073408. Its totient is φ = 5584507200.

The previous prime is 21523649243. The next prime is 21523649261. The reversal of 21523649250 is 5294632512.

It is a junction number, because it is equal to n+sod(n) for n = 21523649199 and 21523649208.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 360064 + ... + 415563.

It is an arithmetic number, because the mean of its divisors is an integer number (862110522).

Almost surely, 2^21523649250 is an apocalyptic number.

21523649250 is an abundant number, since it is smaller than the sum of its proper divisors (33651424158).

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

21523649250 is a wasteful number, since it uses less digits than its factorization.

21523649250 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 775684 (or 775674 counting only the distinct ones).

The product of its (nonzero) digits is 129600, while the sum is 39.

The spelling of 21523649250 in words is "twenty-one billion, five hundred twenty-three million, six hundred forty-nine thousand, two hundred fifty".