31616261 has 2 divisors, whose sum is σ = 31616262. Its totient is φ = 31616260.

The previous prime is 31616257. The next prime is 31616281. The reversal of 31616261 is 16261613.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 31024900 + 591361 = 5570^2 + 769^2 .

It is a cyclic number.

It is not a de Polignac number, because 31616261 - 2² = 31616257 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 31616261.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31616231) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15808130 + 15808131.

It is an arithmetic number, because the mean of its divisors is an integer number (15808131).

Almost surely, 2^31616261 is an apocalyptic number.

It is an amenable number.

31616261 is a deficient number, since it is larger than the sum of its proper divisors (1).

31616261 is an equidigital number, since it uses as much as digits as its factorization.

31616261 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1296, while the sum is 26.

The square root of 31616261 is about 5622.8338940431. The cubic root of 31616261 is about 316.2060458527.

Adding to 31616261 its reverse (16261613), we get a palindrome (47877874).

The spelling of 31616261 in words is "thirty-one million, six hundred sixteen thousand, two hundred sixty-one".