21768006725 has 12 divisors (see below), whose sum is σ = 28165908576. Its totient is φ = 16657256880.

The previous prime is 21768006649. The next prime is 21768006739. The reversal of 21768006725 is 52760086712.

It is not a de Polignac number, because 21768006725 - 2¹⁶ = 21767941189 is a prime.

It is a super-2 number, since 2×21768006725² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

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, 18928127 + ... + 18929276.

It is an arithmetic number, because the mean of its divisors is an integer number (2347159048).

Almost surely, 2^21768006725 is an apocalyptic number.

21768006725 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21768006725 is a deficient number, since it is larger than the sum of its proper divisors (6397901851).

21768006725 is a wasteful number, since it uses less digits than its factorization.

21768006725 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 37857436 (or 37857431 counting only the distinct ones).

The product of its (nonzero) digits is 282240, while the sum is 44.

The spelling of 21768006725 in words is "twenty-one billion, seven hundred sixty-eight million, six thousand, seven hundred twenty-five".