631668161 has 4 divisors (see below), whose sum is σ = 641096112. Its totient is φ = 622240212.

The previous prime is 631668143. The next prime is 631668173. The reversal of 631668161 is 161866136.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 631668161 - 2¹⁴ = 631651777 is a prime.

It is a super-2 number, since 2×631668161² = 798009331242243842, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (631668061) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4713875 + ... + 4714008.

It is an arithmetic number, because the mean of its divisors is an integer number (160274028).

Almost surely, 2^631668161 is an apocalyptic number.

It is an amenable number.

631668161 is a deficient number, since it is larger than the sum of its proper divisors (9427951).

631668161 is an equidigital number, since it uses as much as digits as its factorization.

631668161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9427950.

The product of its digits is 31104, while the sum is 38.

The square root of 631668161 is about 25133.0093900432. The cubic root of 631668161 is about 858.0178620429.

The spelling of 631668161 in words is "six hundred thirty-one million, six hundred sixty-eight thousand, one hundred sixty-one".