631102561 has 4 divisors (see below), whose sum is σ = 631617300. Its totient is φ = 630587824.

The previous prime is 631102541. The next prime is 631102567. The reversal of 631102561 is 165201136.

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 607918336 + 23184225 = 24656^2 + 4815^2 .

It is a cyclic number.

It is not a de Polignac number, because 631102561 - 2¹⁵ = 631069793 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (631102567) 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, 255526 + ... + 257983.

It is an arithmetic number, because the mean of its divisors is an integer number (157904325).

Almost surely, 2^631102561 is an apocalyptic number.

It is an amenable number.

631102561 is a deficient number, since it is larger than the sum of its proper divisors (514739).

631102561 is a wasteful number, since it uses less digits than its factorization.

631102561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 514738.

The product of its (nonzero) digits is 1080, while the sum is 25.

The square root of 631102561 is about 25121.7547356868. The cubic root of 631102561 is about 857.7616938783.

Adding to 631102561 its reverse (165201136), we get a palindrome (796303697).

The spelling of 631102561 in words is "six hundred thirty-one million, one hundred two thousand, five hundred sixty-one".