31630661 has 2 divisors, whose sum is σ = 31630662. Its totient is φ = 31630660.

The previous prime is 31630637. The next prime is 31630663. The reversal of 31630661 is 16603613.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 26368225 + 5262436 = 5135^2 + 2294^2 .

It is a cyclic number.

It is not a de Polignac number, because 31630661 - 2¹⁴ = 31614277 is a prime.

It is a Sophie Germain prime.

Together with 31630663, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is equal to p_1952405 and since 31630661 and 1952405 have the same sum of digits, it is a Honaker prime.

It is a self number, because there is not a number n which added to its sum of digits gives 31630661.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31630663) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15815330 + 15815331.

It is an arithmetic number, because the mean of its divisors is an integer number (15815331).

Almost surely, 2^31630661 is an apocalyptic number.

It is an amenable number.

31630661 is a deficient number, since it is larger than the sum of its proper divisors (1).

31630661 is an equidigital number, since it uses as much as digits as its factorization.

31630661 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1944, while the sum is 26.

The square root of 31630661 is about 5624.1142413717. The cubic root of 31630661 is about 316.2540451607.

The spelling of 31630661 in words is "thirty-one million, six hundred thirty thousand, six hundred sixty-one".