21309239357 has 8 divisors (see below), whose sum is σ = 24589858176. Its totient is φ = 18087730992.

The previous prime is 21309239351. The next prime is 21309239359. The reversal of 21309239357 is 75393290312.

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 21309239357 - 2¹⁰ = 21309238333 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 (21309239351) 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, 14776838 + ... + 14778279.

It is an arithmetic number, because the mean of its divisors is an integer number (3073732272).

Almost surely, 2^21309239357 is an apocalyptic number.

It is an amenable number.

21309239357 is a deficient number, since it is larger than the sum of its proper divisors (3280618819).

21309239357 is a wasteful number, since it uses less digits than its factorization.

21309239357 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29555227.

The product of its (nonzero) digits is 306180, while the sum is 44.

The spelling of 21309239357 in words is "twenty-one billion, three hundred nine million, two hundred thirty-nine thousand, three hundred fifty-seven".