21362563621 has 16 divisors (see below), whose sum is σ = 24857159040. Its totient is φ = 17979698880.

The previous prime is 21362563609. The next prime is 21362563627. The reversal of 21362563621 is 12636526312.

It is a cyclic number.

It is not a de Polignac number, because 21362563621 - 2¹³ = 21362555429 is a prime.

It is a super-2 number, since 2×21362563621² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21362563627) 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 15 ways as a sum of consecutive naturals, for example, 208035 + ... + 293263.

It is an arithmetic number, because the mean of its divisors is an integer number (1553572440).

Almost surely, 2^21362563621 is an apocalyptic number.

It is an amenable number.

21362563621 is a deficient number, since it is larger than the sum of its proper divisors (3494595419).

21362563621 is an equidigital number, since it uses as much as digits as its factorization.

21362563621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 85884.

The product of its digits is 77760, while the sum is 37.

The spelling of 21362563621 in words is "twenty-one billion, three hundred sixty-two million, five hundred sixty-three thousand, six hundred twenty-one".