649031081 has 2 divisors, whose sum is σ = 649031082. Its totient is φ = 649031080.

The previous prime is 649031063. The next prime is 649031129. The reversal of 649031081 is 180130946.

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., 441210025 + 207821056 = 21005^2 + 14416^2 .

It is a cyclic number.

It is not a de Polignac number, because 649031081 - 2²⁶ = 581922217 is a prime.

It is a super-2 number, since 2×649031081² = 842482688208057122, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (649021081) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 324515540 + 324515541.

It is an arithmetic number, because the mean of its divisors is an integer number (324515541).

Almost surely, 2^649031081 is an apocalyptic number.

It is an amenable number.

649031081 is a deficient number, since it is larger than the sum of its proper divisors (1).

649031081 is an equidigital number, since it uses as much as digits as its factorization.

649031081 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5184, while the sum is 32.

The square root of 649031081 is about 25476.0884163955. The cubic root of 649031081 is about 865.8084730774.

The spelling of 649031081 in words is "six hundred forty-nine million, thirty-one thousand, eighty-one".