1561931372 has 12 divisors (see below), whose sum is σ = 2894167080. Its totient is φ = 735026496.

The previous prime is 1561931351. The next prime is 1561931407. The reversal of 1561931372 is 2731391651.

It is a super-2 number, since 2×1561931372² = 4879259221675604768, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11484722 + ... + 11484857.

It is an arithmetic number, because the mean of its divisors is an integer number (241180590).

Almost surely, 2^1561931372 is an apocalyptic number.

It is an amenable number.

1561931372 is a deficient number, since it is larger than the sum of its proper divisors (1332235708).

1561931372 is a wasteful number, since it uses less digits than its factorization.

1561931372 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22969600 (or 22969598 counting only the distinct ones).

The product of its digits is 34020, while the sum is 38.

The square root of 1561931372 is about 39521.2774591106. The cubic root of 1561931372 is about 1160.2564266639.

The spelling of 1561931372 in words is "one billion, five hundred sixty-one million, nine hundred thirty-one thousand, three hundred seventy-two".