21977064942 has 32 divisors (see below), whose sum is σ = 53188192512. Its totient is φ = 5909798784.

The previous prime is 21977064937. The next prime is 21977064943. The reversal of 21977064942 is 24946077912.

It is a Harshad number since it is a multiple of its sum of digits (51).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21977064943) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 15389388 + ... + 15390815.

It is an arithmetic number, because the mean of its divisors is an integer number (1662131016).

Almost surely, 2^21977064942 is an apocalyptic number.

21977064942 is an abundant number, since it is smaller than the sum of its proper divisors (31211127570).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21977064942 is a wasteful number, since it uses less digits than its factorization.

21977064942 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30780232.

The product of its (nonzero) digits is 1524096, while the sum is 51.

The spelling of 21977064942 in words is "twenty-one billion, nine hundred seventy-seven million, sixty-four thousand, nine hundred forty-two".