21053550506 has 24 divisors (see below), whose sum is σ = 32434262784. Its totient is φ = 10248957680.

The previous prime is 21053550491. The next prime is 21053550517. The reversal of 21053550506 is 60505535012.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 721655 + ... + 750261.

It is an arithmetic number, because the mean of its divisors is an integer number (1351427616).

Almost surely, 2^21053550506 is an apocalyptic number.

21053550506 is a deficient number, since it is larger than the sum of its proper divisors (11380712278).

21053550506 is a wasteful number, since it uses less digits than its factorization.

21053550506 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28846 (or 28793 counting only the distinct ones).

The product of its (nonzero) digits is 22500, while the sum is 32.

The spelling of 21053550506 in words is "twenty-one billion, fifty-three million, five hundred fifty thousand, five hundred six".