2506623661 has 2 divisors, whose sum is σ = 2506623662. Its totient is φ = 2506623660.

The previous prime is 2506623653. The next prime is 2506623733. The reversal of 2506623661 is 1663266052.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1434061161 + 1072562500 = 37869^2 + 32750^2 .

It is a cyclic number.

It is not a de Polignac number, because 2506623661 - 2³ = 2506623653 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 2506623661.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2506623061) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1253311830 + 1253311831.

It is an arithmetic number, because the mean of its divisors is an integer number (1253311831).

Almost surely, 2^2506623661 is an apocalyptic number.

It is an amenable number.

2506623661 is a deficient number, since it is larger than the sum of its proper divisors (1).

2506623661 is an equidigital number, since it uses as much as digits as its factorization.

2506623661 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 77760, while the sum is 37.

The square root of 2506623661 is about 50066.1927951387. The cubic root of 2506623661 is about 1358.4063767547.

The spelling of 2506623661 in words is "two billion, five hundred six million, six hundred twenty-three thousand, six hundred sixty-one".