626561261 has 2 divisors, whose sum is σ = 626561262. Its totient is φ = 626561260.

The previous prime is 626561171. The next prime is 626561267. The reversal of 626561261 is 162165626.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 588984361 + 37576900 = 24269^2 + 6130^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-626561261 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (626561267) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 313280630 + 313280631.

It is an arithmetic number, because the mean of its divisors is an integer number (313280631).

Almost surely, 2^626561261 is an apocalyptic number.

It is an amenable number.

626561261 is a deficient number, since it is larger than the sum of its proper divisors (1).

626561261 is an equidigital number, since it uses as much as digits as its factorization.

626561261 is an evil number, because the sum of its binary digits is even.

The product of its digits is 25920, while the sum is 35.

The square root of 626561261 is about 25031.2057440308. The cubic root of 626561261 is about 855.6993063610.

The spelling of 626561261 in words is "six hundred twenty-six million, five hundred sixty-one thousand, two hundred sixty-one".