21402322520 has 16 divisors (see below), whose sum is σ = 48155225760. Its totient is φ = 8560928992.

The previous prime is 21402322519. The next prime is 21402322523. The reversal of 21402322520 is 2522320412.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21402322523) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 267528992 + ... + 267529071.

It is an arithmetic number, because the mean of its divisors is an integer number (3009701610).

Almost surely, 2^21402322520 is an apocalyptic number.

21402322520 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21402322520 is an abundant number, since it is smaller than the sum of its proper divisors (26752903240).

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

21402322520 is a wasteful number, since it uses less digits than its factorization.

21402322520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 535058074 (or 535058070 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 23.

Adding to 21402322520 its reverse (2522320412), we get a palindrome (23924642932).

The spelling of 21402322520 in words is "twenty-one billion, four hundred two million, three hundred twenty-two thousand, five hundred twenty".