21703312615 has 4 divisors (see below), whose sum is σ = 26043975144. Its totient is φ = 17362650088.

The previous prime is 21703312607. The next prime is 21703312651. The reversal of 21703312615 is 51621330712.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21703312615 - 2³ = 21703312607 is a prime.

It is a Duffinian number.

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, 2170331257 + ... + 2170331266.

It is an arithmetic number, because the mean of its divisors is an integer number (6510993786).

Almost surely, 2^21703312615 is an apocalyptic number.

21703312615 is a deficient number, since it is larger than the sum of its proper divisors (4340662529).

21703312615 is an equidigital number, since it uses as much as digits as its factorization.

21703312615 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4340662528.

The product of its (nonzero) digits is 7560, while the sum is 31.

The spelling of 21703312615 in words is "twenty-one billion, seven hundred three million, three hundred twelve thousand, six hundred fifteen".