1561617 has 12 divisors (see below), whose sum is σ = 2271360. Its totient is φ = 1033848.

The previous prime is 1561607. The next prime is 1561633. The reversal of 1561617 is 7161651.

It is not a de Polignac number, because 1561617 - 2⁴ = 1561601 is a prime.

1561617 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1561607) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 984 + ... + 2022.

It is an arithmetic number, because the mean of its divisors is an integer number (189280).

2^1561617 is an apocalyptic number.

It is an amenable number.

1561617 is a deficient number, since it is larger than the sum of its proper divisors (709743).

1561617 is a wasteful number, since it uses less digits than its factorization.

1561617 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1212 (or 1209 counting only the distinct ones).

The product of its digits is 1260, while the sum is 27.

The square root of 1561617 is about 1249.6467500858. The cubic root of 1561617 is about 116.0178579324.

It can be divided in two parts, 156 and 1617, that multiplied together give a palindrome (252252).

The spelling of 1561617 in words is "one million, five hundred sixty-one thousand, six hundred seventeen".