21215470536 has 64 divisors (see below), whose sum is σ = 63465091200. Its totient is φ = 6527836224.

The previous prime is 21215470531. The next prime is 21215470561. The reversal of 21215470536 is 63507451212.

21215470536 is a `hidden beast` number, since 2 + 1 + 2 + 1 + 54 + 70 + 536 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 21215470536.

It is not an unprimeable number, because it can be changed into a prime (21215470531) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3774876 + ... + 3780491.

It is an arithmetic number, because the mean of its divisors is an integer number (991642050).

Almost surely, 2^21215470536 is an apocalyptic number.

21215470536 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is an amenable number.

21215470536 is an abundant number, since it is smaller than the sum of its proper divisors (42249620664).

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

21215470536 is a wasteful number, since it uses less digits than its factorization.

21215470536 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7555395 (or 7555385 counting only the distinct ones).

The product of its (nonzero) digits is 50400, while the sum is 36.

The spelling of 21215470536 in words is "twenty-one billion, two hundred fifteen million, four hundred seventy thousand, five hundred thirty-six".