631616251 has 4 divisors (see below), whose sum is σ = 721847152. Its totient is φ = 541385352.

The previous prime is 631616203. The next prime is 631616257. The reversal of 631616251 is 152616136.

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

It is a cyclic number.

It is not a de Polignac number, because 631616251 - 2⁷ = 631616123 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (631616257) 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, 45115440 + ... + 45115453.

It is an arithmetic number, because the mean of its divisors is an integer number (180461788).

Almost surely, 2^631616251 is an apocalyptic number.

631616251 is a deficient number, since it is larger than the sum of its proper divisors (90230901).

631616251 is an equidigital number, since it uses as much as digits as its factorization.

631616251 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 90230900.

The product of its digits is 6480, while the sum is 31.

The square root of 631616251 is about 25131.9766632074. The cubic root of 631616251 is about 857.9943576513.

The spelling of 631616251 in words is "six hundred thirty-one million, six hundred sixteen thousand, two hundred fifty-one".