21331723605 has 16 divisors (see below), whose sum is σ = 35927113920. Its totient is φ = 10778133888.

The previous prime is 21331723541. The next prime is 21331723619. The reversal of 21331723605 is 50632713312.

It is not a de Polignac number, because 21331723605 - 2⁶ = 21331723541 is a prime.

It is a super-2 number, since 2×21331723605² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 37423792 + ... + 37424361.

It is an arithmetic number, because the mean of its divisors is an integer number (2245444620).

Almost surely, 2^21331723605 is an apocalyptic number.

It is an amenable number.

21331723605 is a deficient number, since it is larger than the sum of its proper divisors (14595390315).

21331723605 is a wasteful number, since it uses less digits than its factorization.

21331723605 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 74848180.

The product of its (nonzero) digits is 22680, while the sum is 33.

The spelling of 21331723605 in words is "twenty-one billion, three hundred thirty-one million, seven hundred twenty-three thousand, six hundred five".