625011661 has 2 divisors, whose sum is σ = 625011662. Its totient is φ = 625011660.

The previous prime is 625011623. The next prime is 625011679. The reversal of 625011661 is 166110526.

625011661 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 493106436 + 131905225 = 22206^2 + 11485^2 .

It is a cyclic number.

It is not a de Polignac number, because 625011661 - 2¹³ = 625003469 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (625015661) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 312505830 + 312505831.

It is an arithmetic number, because the mean of its divisors is an integer number (312505831).

Almost surely, 2^625011661 is an apocalyptic number.

It is an amenable number.

625011661 is a deficient number, since it is larger than the sum of its proper divisors (1).

625011661 is an equidigital number, since it uses as much as digits as its factorization.

625011661 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2160, while the sum is 28.

The square root of 625011661 is about 25000.2332189122. The cubic root of 625011661 is about 854.9932906465.

The spelling of 625011661 in words is "six hundred twenty-five million, eleven thousand, six hundred sixty-one".