1561073868 has 18 divisors (see below), whose sum is σ = 3946047924. Its totient is φ = 520357944.

The previous prime is 1561073837. The next prime is 1561073873. The reversal of 1561073868 is 8683701651.

1561073868 is a `hidden beast` number, since 1 + 561 + 0 + 7 + 3 + 86 + 8 = 666.

It is a tau number, because it is divible by the number of its divisors (18).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 21681546 + ... + 21681617.

Almost surely, 2^1561073868 is an apocalyptic number.

1561073868 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

1561073868 is an abundant number, since it is smaller than the sum of its proper divisors (2384974056).

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

1561073868 is a wasteful number, since it uses less digits than its factorization.

1561073868 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43363173 (or 43363168 counting only the distinct ones).

The product of its (nonzero) digits is 241920, while the sum is 45.

The square root of 1561073868 is about 39510.4273325410. The cubic root of 1561073868 is about 1160.0440599594.

The spelling of 1561073868 in words is "one billion, five hundred sixty-one million, seventy-three thousand, eight hundred sixty-eight".