20689320931 has 2 divisors, whose sum is σ = 20689320932. Its totient is φ = 20689320930.

The previous prime is 20689320907. The next prime is 20689320973. The reversal of 20689320931 is 13902398602.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20689320931 - 2⁷ = 20689320803 is a prime.

It is a super-4 number, since 4×20689320931⁴ (a number of 42 digits) contains 4444 as substring. Note that it is a super-d number also for d = 2.

It is not a weakly prime, because it can be changed into another prime (20689320901) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10344660465 + 10344660466.

It is an arithmetic number, because the mean of its divisors is an integer number (10344660466).

Almost surely, 2^20689320931 is an apocalyptic number.

20689320931 is a deficient number, since it is larger than the sum of its proper divisors (1).

20689320931 is an equidigital number, since it uses as much as digits as its factorization.

20689320931 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 139968, while the sum is 43.

The spelling of 20689320931 in words is "twenty billion, six hundred eighty-nine million, three hundred twenty thousand, nine hundred thirty-one".