1611561 has 24 divisors (see below), whose sum is σ = 2635680. Its totient is φ = 870912.

The previous prime is 1611553. The next prime is 1611563. The reversal of 1611561 is 1651161.

It is not a de Polignac number, because 1611561 - 2³ = 1611553 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is not an unprimeable number, because it can be changed into a prime (1611563) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2505 + ... + 3081.

It is an arithmetic number, because the mean of its divisors is an integer number (109820).

2^1611561 is an apocalyptic number.

It is an amenable number.

1611561 is a deficient number, since it is larger than the sum of its proper divisors (1024119).

1611561 is a wasteful number, since it uses less digits than its factorization.

1611561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 613 (or 606 counting only the distinct ones).

The product of its digits is 180, while the sum is 21.

The square root of 1611561 is about 1269.4727251895. The cubic root of 1611561 is about 117.2417384838.

The spelling of 1611561 in words is "one million, six hundred eleven thousand, five hundred sixty-one".