21008763136 has 27 divisors (see below), whose sum is σ = 41940090451. Its totient is φ = 10503222016.

The previous prime is 21008763119. The next prime is 21008763173. The reversal of 21008763136 is 63136780012.

The square root of 21008763136 is 144944.

It is a perfect power (a square), and thus also a powerful number.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21008763095 and 21008763104.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 2314575 + ... + 2323633.

Almost surely, 2^21008763136 is an apocalyptic number.

21008763136 is the 144944-th square number.

It is an amenable number.

21008763136 is a deficient number, since it is larger than the sum of its proper divisors (20931327315).

21008763136 is an frugal number, since it uses more digits than its factorization.

21008763136 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18134 (or 9061 counting only the distinct ones).

The product of its (nonzero) digits is 36288, while the sum is 37.

It can be divided in two parts, 2100876 and 3136, that added together give a palindrome (2104012).

The spelling of 21008763136 in words is "twenty-one billion, eight million, seven hundred sixty-three thousand, one hundred thirty-six".