21265536590 has 16 divisors (see below), whose sum is σ = 38579369472. Its totient is φ = 8439236064.

The previous prime is 21265536587. The next prime is 21265536601. The reversal of 21265536590 is 9563556212.

It is a congruent number.

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, 8370989 + ... + 8373528.

It is an arithmetic number, because the mean of its divisors is an integer number (2411210592).

Almost surely, 2^21265536590 is an apocalyptic number.

21265536590 is a deficient number, since it is larger than the sum of its proper divisors (17313832882).

21265536590 is a wasteful number, since it uses less digits than its factorization.

21265536590 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16744651.

The product of its (nonzero) digits is 486000, while the sum is 44.

The spelling of 21265536590 in words is "twenty-one billion, two hundred sixty-five million, five hundred thirty-six thousand, five hundred ninety".