21971340439 has 8 divisors (see below), whose sum is σ = 21997984752. Its totient is φ = 21944714880.

The previous prime is 21971340431. The next prime is 21971340493. The reversal of 21971340439 is 93404317912.

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 21971340439 - 2³ = 21971340431 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21971340395 and 21971340404.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21971340431) 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, 4651599 + ... + 4656319.

It is an arithmetic number, because the mean of its divisors is an integer number (2749748094).

Almost surely, 2^21971340439 is an apocalyptic number.

21971340439 is a deficient number, since it is larger than the sum of its proper divisors (26644313).

21971340439 is a wasteful number, since it uses less digits than its factorization.

21971340439 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9377.

The product of its (nonzero) digits is 163296, while the sum is 43.

The spelling of 21971340439 in words is "twenty-one billion, nine hundred seventy-one million, three hundred forty thousand, four hundred thirty-nine".