1561157 has 16 divisors (see below), whose sum is σ = 1799280. Its totient is φ = 1344000.

The previous prime is 1561151. The next prime is 1561159. The reversal of 1561157 is 7511651.

It can be written as a sum of positive squares in 8 ways, for example, as 45796 + 1515361 = 214^2 + 1231^2 .

It is a cyclic number.

It is not a de Polignac number, because 1561157 - 2⁸ = 1560901 is a prime.

It is a super-2 number, since 2×1561157² = 4874422357298, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1561151) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 15407 + ... + 15507.

It is an arithmetic number, because the mean of its divisors is an integer number (112455).

2^1561157 is an apocalyptic number.

It is an amenable number.

1561157 is a deficient number, since it is larger than the sum of its proper divisors (238123).

1561157 is a wasteful number, since it uses less digits than its factorization.

1561157 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 184.

The product of its digits is 1050, while the sum is 26.

The square root of 1561157 is about 1249.4626845168. The cubic root of 1561157 is about 116.0064651569.

The spelling of 1561157 in words is "one million, five hundred sixty-one thousand, one hundred fifty-seven".