231667715621 has 2 divisors, whose sum is σ = 231667715622. Its totient is φ = 231667715620.

The previous prime is 231667715603. The next prime is 231667715641. The reversal of 231667715621 is 126517766132.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 229776422500 + 1891293121 = 479350^2 + 43489^2 .

It is a cyclic number.

It is not a de Polignac number, because 231667715621 - 2¹⁸ = 231667453477 is a prime.

It is a super-2 number, since 2×231667715621² (a number of 24 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (231667715641) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 115833857810 + 115833857811.

It is an arithmetic number, because the mean of its divisors is an integer number (115833857811).

Almost surely, 2^231667715621 is an apocalyptic number.

It is an amenable number.

231667715621 is a deficient number, since it is larger than the sum of its proper divisors (1).

231667715621 is an equidigital number, since it uses as much as digits as its factorization.

231667715621 is an evil number, because the sum of its binary digits is even.

The product of its digits is 635040, while the sum is 47.

The spelling of 231667715621 in words is "two hundred thirty-one billion, six hundred sixty-seven million, seven hundred fifteen thousand, six hundred twenty-one".