21205112510 has 8 divisors (see below), whose sum is σ = 38169202536. Its totient is φ = 8482045000.

The previous prime is 21205112501. The next prime is 21205112521. The reversal of 21205112510 is 1521150212.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1060255616 + ... + 1060255635.

It is an arithmetic number, because the mean of its divisors is an integer number (4771150317).

Almost surely, 2^21205112510 is an apocalyptic number.

21205112510 is a deficient number, since it is larger than the sum of its proper divisors (16964090026).

21205112510 is a wasteful number, since it uses less digits than its factorization.

21205112510 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2120511258.

The product of its (nonzero) digits is 200, while the sum is 20.

Adding to 21205112510 its reverse (1521150212), we get a palindrome (22726262722).

The spelling of 21205112510 in words is "twenty-one billion, two hundred five million, one hundred twelve thousand, five hundred ten".