21955331970 has 96 divisors (see below), whose sum is σ = 67063598784. Its totient is φ = 4913078400.

The previous prime is 21955331933. The next prime is 21955331971. The reversal of 21955331970 is 7913355912.

21955331970 is a `hidden beast` number, since 2 + 1 + 9 + 553 + 3 + 1 + 97 + 0 = 666.

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21955331971) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 840096 + ... + 865835.

It is an arithmetic number, because the mean of its divisors is an integer number (698579154).

Almost surely, 2^21955331970 is an apocalyptic number.

21955331970 is an abundant number, since it is smaller than the sum of its proper divisors (45108266814).

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

21955331970 is a wasteful number, since it uses less digits than its factorization.

21955331970 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1705968 (or 1705965 counting only the distinct ones).

The product of its (nonzero) digits is 255150, while the sum is 45.

The spelling of 21955331970 in words is "twenty-one billion, nine hundred fifty-five million, three hundred thirty-one thousand, nine hundred seventy".