21755372394 has 16 divisors (see below), whose sum is σ = 49726565568. Its totient is φ = 6215820672.

The previous prime is 21755372393. The next prime is 21755372467. The reversal of 21755372394 is 49327355712.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21755372393) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 258992487 + ... + 258992570.

It is an arithmetic number, because the mean of its divisors is an integer number (3107910348).

Almost surely, 2^21755372394 is an apocalyptic number.

21755372394 is an abundant number, since it is smaller than the sum of its proper divisors (27971193174).

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

21755372394 is a wasteful number, since it uses less digits than its factorization.

21755372394 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 517985069.

The product of its digits is 1587600, while the sum is 48.

The spelling of 21755372394 in words is "twenty-one billion, seven hundred fifty-five million, three hundred seventy-two thousand, three hundred ninety-four".