21715221670 has 32 divisors (see below), whose sum is σ = 39667737888. Its totient is φ = 8557394688.

The previous prime is 21715221667. The next prime is 21715221709. The reversal of 21715221670 is 7612251712.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 645712 + ... + 678508.

It is an arithmetic number, because the mean of its divisors is an integer number (1239616809).

Almost surely, 2^21715221670 is an apocalyptic number.

21715221670 is a deficient number, since it is larger than the sum of its proper divisors (17952516218).

21715221670 is a wasteful number, since it uses less digits than its factorization.

21715221670 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33784.

The product of its (nonzero) digits is 11760, while the sum is 34.

The spelling of 21715221670 in words is "twenty-one billion, seven hundred fifteen million, two hundred twenty-one thousand, six hundred seventy".