231708867661 has 4 divisors (see below), whose sum is σ = 234097618972. Its totient is φ = 229320116352.

The previous prime is 231708867641. The next prime is 231708867667. The reversal of 231708867661 is 166768807132.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 156471669225 + 75237198436 = 395565^2 + 274294^2 .

It is a cyclic number.

It is not a de Polignac number, because 231708867661 - 2³³ = 223118933069 is a prime.

It is a super-2 number, since 2×231708867661² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (231708867667) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1194375510 + ... + 1194375703.

It is an arithmetic number, because the mean of its divisors is an integer number (58524404743).

Almost surely, 2^231708867661 is an apocalyptic number.

It is an amenable number.

231708867661 is a deficient number, since it is larger than the sum of its proper divisors (2388751311).

231708867661 is an equidigital number, since it uses as much as digits as its factorization.

231708867661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2388751310.

The product of its (nonzero) digits is 4064256, while the sum is 55.

The spelling of 231708867661 in words is "two hundred thirty-one billion, seven hundred eight million, eight hundred sixty-seven thousand, six hundred sixty-one".