21216360020 has 24 divisors (see below), whose sum is σ = 44621992800. Its totient is φ = 8473660832.

The previous prime is 21216359993. The next prime is 21216360047. The reversal of 21216360020 is 2006361212.

It is an interprime number because it is at equal distance from previous prime (21216359993) and next prime (21216360047).

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 791690 + ... + 818049.

It is an arithmetic number, because the mean of its divisors is an integer number (1859249700).

Almost surely, 2^21216360020 is an apocalyptic number.

21216360020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21216360020 is an abundant number, since it is smaller than the sum of its proper divisors (23405632780).

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

21216360020 is a wasteful number, since it uses less digits than its factorization.

21216360020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1610407 (or 1610405 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 23.

The spelling of 21216360020 in words is "twenty-one billion, two hundred sixteen million, three hundred sixty thousand, twenty".