1261617697 has 2 divisors, whose sum is σ = 1261617698. Its totient is φ = 1261617696.

The previous prime is 1261617691. The next prime is 1261617713. The reversal of 1261617697 is 7967161621.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1260534016 + 1083681 = 35504^2 + 1041^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1261617697 is a prime.

It is not a weakly prime, because it can be changed into another prime (1261617691) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 630808848 + 630808849.

It is an arithmetic number, because the mean of its divisors is an integer number (630808849).

Almost surely, 2^1261617697 is an apocalyptic number.

It is an amenable number.

1261617697 is a deficient number, since it is larger than the sum of its proper divisors (1).

1261617697 is an equidigital number, since it uses as much as digits as its factorization.

1261617697 is an evil number, because the sum of its binary digits is even.

The product of its digits is 190512, while the sum is 46.

The square root of 1261617697 is about 35519.2581144370. The cubic root of 1261617697 is about 1080.5443349408.

The spelling of 1261617697 in words is "one billion, two hundred sixty-one million, six hundred seventeen thousand, six hundred ninety-seven".