1561117907 has 2 divisors, whose sum is σ = 1561117908. Its totient is φ = 1561117906.

The previous prime is 1561117823. The next prime is 1561117931. The reversal of 1561117907 is 7097111651.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1561117907 - 2⁸ = 1561117651 is a prime.

It is not a weakly prime, because it can be changed into another prime (1561117507) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 780558953 + 780558954.

It is an arithmetic number, because the mean of its divisors is an integer number (780558954).

Almost surely, 2^1561117907 is an apocalyptic number.

1561117907 is a deficient number, since it is larger than the sum of its proper divisors (1).

1561117907 is an equidigital number, since it uses as much as digits as its factorization.

1561117907 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 13230, while the sum is 38.

The square root of 1561117907 is about 39510.9846371867. The cubic root of 1561117907 is about 1160.0549684118.

The spelling of 1561117907 in words is "one billion, five hundred sixty-one million, one hundred seventeen thousand, nine hundred seven".