21707431421 has 8 divisors (see below), whose sum is σ = 23874622464. Its totient is φ = 19611295920.

The previous prime is 21707431387. The next prime is 21707431457. The reversal of 21707431421 is 12413470712.

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

It is a cyclic number.

It is not a de Polignac number, because 21707431421 - 2⁶ = 21707431357 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21707431481) 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, 17763245 + ... + 17764466.

It is an arithmetic number, because the mean of its divisors is an integer number (2984327808).

Almost surely, 2^21707431421 is an apocalyptic number.

It is an amenable number.

21707431421 is a deficient number, since it is larger than the sum of its proper divisors (2167191043).

21707431421 is a wasteful number, since it uses less digits than its factorization.

21707431421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35527771.

The product of its (nonzero) digits is 9408, while the sum is 32.

The spelling of 21707431421 in words is "twenty-one billion, seven hundred seven million, four hundred thirty-one thousand, four hundred twenty-one".