631357661 has 4 divisors (see below), whose sum is σ = 688753824. Its totient is φ = 573961500.

The previous prime is 631357633. The next prime is 631357681. The reversal of 631357661 is 166753136.

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 a de Polignac number, because none of the positive numbers 2^k-631357661 is a prime.

It is a super-2 number, since 2×631357661² = 797224992206781842, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (631357681) 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, 28698065 + ... + 28698086.

It is an arithmetic number, because the mean of its divisors is an integer number (172188456).

Almost surely, 2^631357661 is an apocalyptic number.

It is an amenable number.

631357661 is a deficient number, since it is larger than the sum of its proper divisors (57396163).

631357661 is a wasteful number, since it uses less digits than its factorization.

631357661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 57396162.

The product of its digits is 68040, while the sum is 38.

The square root of 631357661 is about 25126.8314954353. The cubic root of 631357661 is about 857.8772511826.

The spelling of 631357661 in words is "six hundred thirty-one million, three hundred fifty-seven thousand, six hundred sixty-one".