21979393425 has 144 divisors (see below), whose sum is σ = 43931384640. Its totient is φ = 10414656000.

The previous prime is 21979393417. The next prime is 21979393463. The reversal of 21979393425 is 52439397912.

It is not a de Polignac number, because 21979393425 - 2³ = 21979393417 is a prime.

It is an unprimeable number.

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 143 ways as a sum of consecutive naturals, for example, 29741706 + ... + 29742444.

It is an arithmetic number, because the mean of its divisors is an integer number (305079060).

Almost surely, 2^21979393425 is an apocalyptic number.

21979393425 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21979393425 is a deficient number, since it is larger than the sum of its proper divisors (21951991215).

21979393425 is a wasteful number, since it uses less digits than its factorization.

21979393425 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1024 (or 1016 counting only the distinct ones).

The product of its digits is 3674160, while the sum is 54.

The spelling of 21979393425 in words is "twenty-one billion, nine hundred seventy-nine million, three hundred ninety-three thousand, four hundred twenty-five".