1561795020 has 84 divisors (see below), whose sum is σ = 4917450720. Its totient is φ = 416474784.

The previous prime is 1561795019. The next prime is 1561795033. The reversal of 1561795020 is 205971651.

1561795020 is a `hidden beast` number, since 1 + 561 + 7 + 95 + 0 + 2 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 27 ways as a sum of consecutive naturals, for example, 38980 + ... + 68139.

It is an arithmetic number, because the mean of its divisors is an integer number (58541080).

Almost surely, 2^1561795020 is an apocalyptic number.

1561795020 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1561795020 is an abundant number, since it is smaller than the sum of its proper divisors (3355655700).

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

1561795020 is a wasteful number, since it uses less digits than its factorization.

1561795020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 107146 (or 107129 counting only the distinct ones).

The product of its (nonzero) digits is 18900, while the sum is 36.

The square root of 1561795020 is about 39519.5523760075. The cubic root of 1561795020 is about 1160.2226633606. Note that the first 3 decimals are identical.

The spelling of 1561795020 in words is "one billion, five hundred sixty-one million, seven hundred ninety-five thousand, twenty".