631550661 has 24 divisors (see below), whose sum is σ = 1013332320. Its totient is φ = 348439392.

The previous prime is 631550657. The next prime is 631550681. The reversal of 631550661 is 166055136.

It is not a de Polignac number, because 631550661 - 2² = 631550657 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (631550651) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 69811 + ... + 78336.

It is an arithmetic number, because the mean of its divisors is an integer number (42222180).

Almost surely, 2^631550661 is an apocalyptic number.

It is an amenable number.

631550661 is a deficient number, since it is larger than the sum of its proper divisors (381781659).

631550661 is a wasteful number, since it uses less digits than its factorization.

631550661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 148193 (or 148186 counting only the distinct ones).

The product of its (nonzero) digits is 16200, while the sum is 33.

The square root of 631550661 is about 25130.6717180421. The cubic root of 631550661 is about 857.9646572344.

The spelling of 631550661 in words is "six hundred thirty-one million, five hundred fifty thousand, six hundred sixty-one".