21002565226 has 16 divisors (see below), whose sum is σ = 32432571360. Its totient is φ = 10193063760.

The previous prime is 21002565209. The next prime is 21002565251. The reversal of 21002565226 is 62256520012.

It is a happy number.

It is a super-2 number, since 2×21002565226² (a number of 21 digits) contains 22 as substring.

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, 307680 + ... + 369691.

It is an arithmetic number, because the mean of its divisors is an integer number (2027035710).

Almost surely, 2^21002565226 is an apocalyptic number.

21002565226 is a deficient number, since it is larger than the sum of its proper divisors (11430006134).

21002565226 is a wasteful number, since it uses less digits than its factorization.

21002565226 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 677829.

The product of its (nonzero) digits is 14400, while the sum is 31.

The spelling of 21002565226 in words is "twenty-one billion, two million, five hundred sixty-five thousand, two hundred twenty-six".