1561055 has 4 divisors (see below), whose sum is σ = 1873272. Its totient is φ = 1248840.

The previous prime is 1561039. The next prime is 1561069. The reversal of 1561055 is 5501651.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5501651 = 61 ⋅90191.

It is not a de Polignac number, because 1561055 - 2⁴ = 1561039 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1561055.

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, 156101 + ... + 156110.

It is an arithmetic number, because the mean of its divisors is an integer number (468318).

2^1561055 is an apocalyptic number.

1561055 is a deficient number, since it is larger than the sum of its proper divisors (312217).

1561055 is an equidigital number, since it uses as much as digits as its factorization.

1561055 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 312216.

The product of its (nonzero) digits is 750, while the sum is 23.

The square root of 1561055 is about 1249.4218663046. The cubic root of 1561055 is about 116.0039386296.

The spelling of 1561055 in words is "one million, five hundred sixty-one thousand, fifty-five".