21707421723 has 48 divisors (see below), whose sum is σ = 35068633600. Its totient is φ = 12852810432.

The previous prime is 21707421709. The next prime is 21707421731. The reversal of 21707421723 is 32712470712.

It is not a de Polignac number, because 21707421723 - 2²⁰ = 21706373147 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21707421773) by changing a digit.

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 47 ways as a sum of consecutive naturals, for example, 304878 + ... + 369276.

Almost surely, 2^21707421723 is an apocalyptic number.

21707421723 is a deficient number, since it is larger than the sum of its proper divisors (13361211877).

21707421723 is a wasteful number, since it uses less digits than its factorization.

21707421723 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 64528 (or 64525 counting only the distinct ones).

The product of its (nonzero) digits is 32928, while the sum is 36.

The spelling of 21707421723 in words is "twenty-one billion, seven hundred seven million, four hundred twenty-one thousand, seven hundred twenty-three".