21657253328 has 20 divisors (see below), whose sum is σ = 42853715520. Its totient is φ = 10598229984.

The previous prime is 21657253291. The next prime is 21657253333. The reversal of 21657253328 is 82335275612.

It is a happy number.

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 3 ways as a sum of consecutive naturals, for example, 14399018 + ... + 14400521.

It is an arithmetic number, because the mean of its divisors is an integer number (2142685776).

Almost surely, 2^21657253328 is an apocalyptic number.

It is an amenable number.

21657253328 is a deficient number, since it is larger than the sum of its proper divisors (21196462192).

21657253328 is a wasteful number, since it uses less digits than its factorization.

21657253328 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28799594 (or 28799588 counting only the distinct ones).

The product of its digits is 604800, while the sum is 44.

The spelling of 21657253328 in words is "twenty-one billion, six hundred fifty-seven million, two hundred fifty-three thousand, three hundred twenty-eight".