1561081 has 4 divisors (see below), whose sum is σ = 1587600. Its totient is φ = 1534564.

The previous prime is 1561069. The next prime is 1561111. The reversal of 1561081 is 1801651.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1801651 = 47 ⋅38333.

It is a cyclic number.

It is not a de Polignac number, because 1561081 - 2⁷ = 1560953 is a prime.

It is a super-2 number, since 2×1561081² = 4873947777122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1562081) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13171 + ... + 13288.

It is an arithmetic number, because the mean of its divisors is an integer number (396900).

2^1561081 is an apocalyptic number.

It is an amenable number.

1561081 is a deficient number, since it is larger than the sum of its proper divisors (26519).

1561081 is an equidigital number, since it uses as much as digits as its factorization.

1561081 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26518.

The product of its (nonzero) digits is 240, while the sum is 22.

The square root of 1561081 is about 1249.4322710735. The cubic root of 1561081 is about 116.0045826568.

The spelling of 1561081 in words is "one million, five hundred sixty-one thousand, eighty-one".