649566254261 has 2 divisors, whose sum is σ = 649566254262. Its totient is φ = 649566254260.

The previous prime is 649566254221. The next prime is 649566254269. The reversal of 649566254261 is 162452665946.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 397049954161 + 252516300100 = 630119^2 + 502510^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-649566254261 is a prime.

It is a super-2 number, since 2×649566254261² (a number of 24 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 649566254197 and 649566254206.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (649566254269) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 324783127130 + 324783127131.

It is an arithmetic number, because the mean of its divisors is an integer number (324783127131).

Almost surely, 2^649566254261 is an apocalyptic number.

It is an amenable number.

649566254261 is a deficient number, since it is larger than the sum of its proper divisors (1).

649566254261 is an equidigital number, since it uses as much as digits as its factorization.

649566254261 is an evil number, because the sum of its binary digits is even.

The product of its digits is 18662400, while the sum is 56.

The spelling of 649566254261 in words is "six hundred forty-nine billion, five hundred sixty-six million, two hundred fifty-four thousand, two hundred sixty-one".