21615844970 has 8 divisors (see below), whose sum is σ = 38908520964. Its totient is φ = 8646337984.

The previous prime is 21615844949. The next prime is 21615845029. The reversal of 21615844970 is 7944851612.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 20739744169 + 876100801 = 144013^2 + 29599^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1080792239 + ... + 1080792258.

Almost surely, 2^21615844970 is an apocalyptic number.

21615844970 is a deficient number, since it is larger than the sum of its proper divisors (17292675994).

21615844970 is a wasteful number, since it uses less digits than its factorization.

21615844970 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2161584504.

The product of its (nonzero) digits is 483840, while the sum is 47.

The spelling of 21615844970 in words is "twenty-one billion, six hundred fifteen million, eight hundred forty-four thousand, nine hundred seventy".