21750646857 has 8 divisors (see below), whose sum is σ = 29063501184. Its totient is φ = 14469111888.

The previous prime is 21750646849. The next prime is 21750646861. The reversal of 21750646857 is 75864605712.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21750646857 - 2³ = 21750646849 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21750646807) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7828218 + ... + 7830995.

It is an arithmetic number, because the mean of its divisors is an integer number (3632937648).

Almost surely, 2^21750646857 is an apocalyptic number.

It is an amenable number.

21750646857 is a deficient number, since it is larger than the sum of its proper divisors (7312854327).

21750646857 is a wasteful number, since it uses less digits than its factorization.

21750646857 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15659679.

The product of its (nonzero) digits is 2822400, while the sum is 51.

The spelling of 21750646857 in words is "twenty-one billion, seven hundred fifty million, six hundred forty-six thousand, eight hundred fifty-seven".