21115053240 has 64 divisors (see below), whose sum is σ = 63354713760. Its totient is φ = 5629831680.

The previous prime is 21115053227. The next prime is 21115053277. The reversal of 21115053240 is 4235051112.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a self number, because there is not a number n which added to its sum of digits gives 21115053240.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1546122 + ... + 1559718.

Almost surely, 2^21115053240 is an apocalyptic number.

21115053240 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21115053240 is an abundant number, since it is smaller than the sum of its proper divisors (42239660520).

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

21115053240 is a wasteful number, since it uses less digits than its factorization.

21115053240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26552 (or 26548 counting only the distinct ones).

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

The spelling of 21115053240 in words is "twenty-one billion, one hundred fifteen million, fifty-three thousand, two hundred forty".