21957158782 has 16 divisors (see below), whose sum is σ = 35500888080. Its totient is φ = 10125035712.

The previous prime is 21957158779. The next prime is 21957158813. The reversal of 21957158782 is 28785175912.

It is a happy number.

21957158782 is digitally balanced in base 5, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 346807 + ... + 405202.

It is an arithmetic number, because the mean of its divisors is an integer number (2218805505).

Almost surely, 2^21957158782 is an apocalyptic number.

21957158782 is a deficient number, since it is larger than the sum of its proper divisors (13543729298).

21957158782 is a wasteful number, since it uses less digits than its factorization.

21957158782 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 753147.

The product of its digits is 2822400, while the sum is 55.

The spelling of 21957158782 in words is "twenty-one billion, nine hundred fifty-seven million, one hundred fifty-eight thousand, seven hundred eighty-two".