1561996895 has 8 divisors (see below), whose sum is σ = 1880311104. Its totient is φ = 1245654304.

The previous prime is 1561996879. The next prime is 1561996901. The reversal of 1561996895 is 5986991651.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1561996895 - 2⁴ = 1561996879 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 491159 + ... + 494328.

It is an arithmetic number, because the mean of its divisors is an integer number (235038888).

Almost surely, 2^1561996895 is an apocalyptic number.

1561996895 is a deficient number, since it is larger than the sum of its proper divisors (318314209).

1561996895 is an equidigital number, since it uses as much as digits as its factorization.

1561996895 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 985809.

The product of its digits is 5248800, while the sum is 59.

The square root of 1561996895 is about 39522.1064089454. The cubic root of 1561996895 is about 1160.2726506842.

The spelling of 1561996895 in words is "one billion, five hundred sixty-one million, nine hundred ninety-six thousand, eight hundred ninety-five".