631726661 has 2 divisors, whose sum is σ = 631726662. Its totient is φ = 631726660.

The previous prime is 631726657. The next prime is 631726673. The reversal of 631726661 is 166627136.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 567630625 + 64096036 = 23825^2 + 8006^2 .

It is a cyclic number.

It is not a de Polignac number, because 631726661 - 2² = 631726657 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (631726651) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 315863330 + 315863331.

It is an arithmetic number, because the mean of its divisors is an integer number (315863331).

Almost surely, 2^631726661 is an apocalyptic number.

It is an amenable number.

631726661 is a deficient number, since it is larger than the sum of its proper divisors (1).

631726661 is an equidigital number, since it uses as much as digits as its factorization.

631726661 is an evil number, because the sum of its binary digits is even.

The product of its digits is 54432, while the sum is 38.

The square root of 631726661 is about 25134.1731712026. The cubic root of 631726661 is about 858.0443487852.

The spelling of 631726661 in words is "six hundred thirty-one million, seven hundred twenty-six thousand, six hundred sixty-one".