31005649 has 2 divisors, whose sum is σ = 31005650. Its totient is φ = 31005648.

The previous prime is 31005647. The next prime is 31005659. The reversal of 31005649 is 94650013.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 31002624 + 3025 = 5568^2 + 55^2 .

It is a cyclic number.

It is not a de Polignac number, because 31005649 - 2¹ = 31005647 is a prime.

It is a super-2 number, since 2×31005649² = 1922700539822402, which contains 22 as substring.

Together with 31005647, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (31005647) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15502824 + 15502825.

It is an arithmetic number, because the mean of its divisors is an integer number (15502825).

Almost surely, 2^31005649 is an apocalyptic number.

It is an amenable number.

31005649 is a deficient number, since it is larger than the sum of its proper divisors (1).

31005649 is an equidigital number, since it uses as much as digits as its factorization.

31005649 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3240, while the sum is 28.

The square root of 31005649 is about 5568.2716348971. The cubic root of 31005649 is about 314.1571454343.

The spelling of 31005649 in words is "thirty-one million, five thousand, six hundred forty-nine".