21215036502 has 24 divisors (see below), whose sum is σ = 50144632200. Its totient is φ = 6428798880.

The previous prime is 21215036461. The next prime is 21215036551. The reversal of 21215036502 is 20563051212.

It is a happy number.

21215036502 is a `hidden beast` number, since 2 + 1 + 2 + 1 + 5 + 0 + 3 + 650 + 2 = 666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 53573127 + ... + 53573522.

It is an arithmetic number, because the mean of its divisors is an integer number (2089359675).

Almost surely, 2^21215036502 is an apocalyptic number.

21215036502 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

21215036502 is an abundant number, since it is smaller than the sum of its proper divisors (28929595698).

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

21215036502 is a wasteful number, since it uses less digits than its factorization.

21215036502 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 107146668 (or 107146665 counting only the distinct ones).

The product of its (nonzero) digits is 3600, while the sum is 27.

Adding to 21215036502 its reverse (20563051212), we get a palindrome (41778087714).

The spelling of 21215036502 in words is "twenty-one billion, two hundred fifteen million, thirty-six thousand, five hundred two".