1561976871 has 48 divisors (see below), whose sum is σ = 2746396800. Its totient is φ = 780518592.

The previous prime is 1561976837. The next prime is 1561976873. The reversal of 1561976871 is 1786791651.

It is not a de Polignac number, because 1561976871 - 2⁶ = 1561976807 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1561976873) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 14800 + ... + 57818.

It is an arithmetic number, because the mean of its divisors is an integer number (57216600).

Almost surely, 2^1561976871 is an apocalyptic number.

1561976871 is a deficient number, since it is larger than the sum of its proper divisors (1184419929).

1561976871 is a wasteful number, since it uses less digits than its factorization.

1561976871 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43068 (or 43061 counting only the distinct ones).

The product of its digits is 635040, while the sum is 51.

The square root of 1561976871 is about 39521.8530815548. The cubic root of 1561976871 is about 1160.2676926294.

The spelling of 1561976871 in words is "one billion, five hundred sixty-one million, nine hundred seventy-six thousand, eight hundred seventy-one".