21764392390 has 32 divisors (see below), whose sum is σ = 44023766976. Its totient is φ = 7686687360.

The previous prime is 21764392373. The next prime is 21764392393. The reversal of 21764392390 is 9329346712.

It is a super-2 number, since 2×21764392390² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (46).

It is a self number, because there is not a number n which added to its sum of digits gives 21764392390.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21764392393) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3636541 + ... + 3642520.

It is an arithmetic number, because the mean of its divisors is an integer number (1375742718).

Almost surely, 2^21764392390 is an apocalyptic number.

21764392390 is an abundant number, since it is smaller than the sum of its proper divisors (22259374586).

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

21764392390 is a wasteful number, since it uses less digits than its factorization.

21764392390 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7279104.

The product of its (nonzero) digits is 489888, while the sum is 46.

The spelling of 21764392390 in words is "twenty-one billion, seven hundred sixty-four million, three hundred ninety-two thousand, three hundred ninety".