1561167655 has 4 divisors (see below), whose sum is σ = 1873401192. Its totient is φ = 1248934120.

The previous prime is 1561167617. The next prime is 1561167683. The reversal of 1561167655 is 5567611651.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 1561167655 - 2⁹ = 1561167143 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 3 ways as a sum of consecutive naturals, for example, 156116761 + ... + 156116770.

It is an arithmetic number, because the mean of its divisors is an integer number (468350298).

Almost surely, 2^1561167655 is an apocalyptic number.

1561167655 is a deficient number, since it is larger than the sum of its proper divisors (312233537).

1561167655 is an equidigital number, since it uses as much as digits as its factorization.

1561167655 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 312233536.

The product of its digits is 189000, while the sum is 43.

The square root of 1561167655 is about 39511.6141786184. The cubic root of 1561167655 is about 1160.0672907358.

The spelling of 1561167655 in words is "one billion, five hundred sixty-one million, one hundred sixty-seven thousand, six hundred fifty-five".