21424772457 has 64 divisors (see below), whose sum is σ = 36487065600. Its totient is φ = 12288231360.

The previous prime is 21424772437. The next prime is 21424772497. The reversal of 21424772457 is 75427742412.

It is not a de Polignac number, because 21424772457 - 2⁷ = 21424772329 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21424772407) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 8423728 + ... + 8426270.

It is an arithmetic number, because the mean of its divisors is an integer number (570110400).

Almost surely, 2^21424772457 is an apocalyptic number.

21424772457 is a gapful number since it is divisible by the number (27) formed by its first and last digit.

It is an amenable number.

21424772457 is a deficient number, since it is larger than the sum of its proper divisors (15062293143).

21424772457 is a wasteful number, since it uses less digits than its factorization.

21424772457 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4075 (or 4069 counting only the distinct ones).

The product of its digits is 878080, while the sum is 45.

It can be divided in two parts, 21424 and 772457, that added together give a square (793881 = 891²).

The spelling of 21424772457 in words is "twenty-one billion, four hundred twenty-four million, seven hundred seventy-two thousand, four hundred fifty-seven".