1561117908 has 48 divisors (see below), whose sum is σ = 4306538880. Its totient is φ = 430652544.

The previous prime is 1561117907. The next prime is 1561117931. The reversal of 1561117908 is 8097111651.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1561117907) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 317991 + ... + 322862.

It is an arithmetic number, because the mean of its divisors is an integer number (89719560).

Almost surely, 2^1561117908 is an apocalyptic number.

It is an amenable number.

1561117908 is an abundant number, since it is smaller than the sum of its proper divisors (2745420972).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1561117908 is a wasteful number, since it uses less digits than its factorization.

1561117908 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 640896 (or 640894 counting only the distinct ones).

The product of its (nonzero) digits is 15120, while the sum is 39.

The square root of 1561117908 is about 39510.9846498414. The cubic root of 1561117908 is about 1160.0549686595.

The spelling of 1561117908 in words is "one billion, five hundred sixty-one million, one hundred seventeen thousand, nine hundred eight".