21339902691 has 12 divisors (see below), whose sum is σ = 30825781480. Its totient is φ = 14225919840.

The previous prime is 21339902657. The next prime is 21339902707. The reversal of 21339902691 is 19620993312.

It is not a de Polignac number, because 21339902691 - 2¹⁴ = 21339886307 is a prime.

It is a super-2 number, since 2×21339902691² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21339902621) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 204696 + ... + 290826.

Almost surely, 2^21339902691 is an apocalyptic number.

21339902691 is a deficient number, since it is larger than the sum of its proper divisors (9485878789).

21339902691 is a wasteful number, since it uses less digits than its factorization.

21339902691 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 113666 (or 113663 counting only the distinct ones).

The product of its (nonzero) digits is 157464, while the sum is 45.

The spelling of 21339902691 in words is "twenty-one billion, three hundred thirty-nine million, nine hundred two thousand, six hundred ninety-one".