1561611055 has 8 divisors (see below), whose sum is σ = 1874192112. Its totient is φ = 1249116288.

The previous prime is 1561611031. The next prime is 1561611061. The reversal of 1561611055 is 5501161651.

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 1561611055 - 2²⁵ = 1528056623 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, 29047 + ... + 62983.

It is an arithmetic number, because the mean of its divisors is an integer number (234274014).

Almost surely, 2^1561611055 is an apocalyptic number.

1561611055 is a deficient number, since it is larger than the sum of its proper divisors (312581057).

1561611055 is an equidigital number, since it uses as much as digits as its factorization.

1561611055 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43145.

The product of its (nonzero) digits is 4500, while the sum is 31.

The square root of 1561611055 is about 39517.2247886918. The cubic root of 1561611055 is about 1160.1771070743.

The spelling of 1561611055 in words is "one billion, five hundred sixty-one million, six hundred eleven thousand, fifty-five".