21688973925 has 48 divisors (see below), whose sum is σ = 36094743360. Its totient is φ = 11491683840.

The previous prime is 21688973923. The next prime is 21688974071. The reversal of 21688973925 is 52937988612.

It is not a de Polignac number, because 21688973925 - 2¹ = 21688973923 is a prime.

It is a super-3 number, since 3×21688973925³ (a number of 32 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21688973921) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 9557691 + ... + 9559959.

It is an arithmetic number, because the mean of its divisors is an integer number (751973820).

Almost surely, 2^21688973925 is an apocalyptic number.

21688973925 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21688973925 is a deficient number, since it is larger than the sum of its proper divisors (14405769435).

21688973925 is a wasteful number, since it uses less digits than its factorization.

21688973925 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3062 (or 3057 counting only the distinct ones).

The product of its digits is 13063680, while the sum is 60.

The spelling of 21688973925 in words is "twenty-one billion, six hundred eighty-eight million, nine hundred seventy-three thousand, nine hundred twenty-five".