21580716723 has 8 divisors (see below), whose sum is σ = 28779758736. Its totient is φ = 14384409600.

The previous prime is 21580716709. The next prime is 21580716733. The reversal of 21580716723 is 32761708512.

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

It is not a de Polignac number, because 21580716723 - 2⁶ = 21580716659 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21580716733) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 665238 + ... + 696923.

It is an arithmetic number, because the mean of its divisors is an integer number (3597469842).

Almost surely, 2^21580716723 is an apocalyptic number.

21580716723 is a deficient number, since it is larger than the sum of its proper divisors (7199042013).

21580716723 is a wasteful number, since it uses less digits than its factorization.

21580716723 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1367445.

The product of its (nonzero) digits is 141120, while the sum is 42.

The spelling of 21580716723 in words is "twenty-one billion, five hundred eighty million, seven hundred sixteen thousand, seven hundred twenty-three".