21670871231 has 2 divisors, whose sum is σ = 21670871232. Its totient is φ = 21670871230.

The previous prime is 21670871197. The next prime is 21670871279. The reversal of 21670871231 is 13217807612.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21670871231 is a prime.

It is a super-2 number, since 2×21670871231² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21670871291) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10835435615 + 10835435616.

It is an arithmetic number, because the mean of its divisors is an integer number (10835435616).

Almost surely, 2^21670871231 is an apocalyptic number.

21670871231 is a deficient number, since it is larger than the sum of its proper divisors (1).

21670871231 is an equidigital number, since it uses as much as digits as its factorization.

21670871231 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 28224, while the sum is 38.

The spelling of 21670871231 in words is "twenty-one billion, six hundred seventy million, eight hundred seventy-one thousand, two hundred thirty-one".