21502312152 has 16 divisors (see below), whose sum is σ = 53755780440. Its totient is φ = 7167437376.

The previous prime is 21502312129. The next prime is 21502312213. The reversal of 21502312152 is 25121320512.

It is a super-2 number, since 2×21502312152² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (24), and also a Moran number because the ratio is a prime number: 895929673 = 21502312152 / (2 + 1 + 5 + 0 + 2 + 3 + 1 + 2 + 1 + 5 + 2).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 447964813 + ... + 447964860.

Almost surely, 2^21502312152 is an apocalyptic number.

It is an amenable number.

21502312152 is an abundant number, since it is smaller than the sum of its proper divisors (32253468288).

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

21502312152 is a wasteful number, since it uses less digits than its factorization.

21502312152 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 895929682 (or 895929678 counting only the distinct ones).

The product of its (nonzero) digits is 1200, while the sum is 24.

Adding to 21502312152 its reverse (25121320512), we get a palindrome (46623632664).

The spelling of 21502312152 in words is "twenty-one billion, five hundred two million, three hundred twelve thousand, one hundred fifty-two".