1911561 has 8 divisors (see below), whose sum is σ = 2567904. Its totient is φ = 1264800.

The previous prime is 1911529. The next prime is 1911583. The reversal of 1911561 is 1651191.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1911561 - 2⁵ = 1911529 is a prime.

1911561 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (1911061) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1915 + ... + 2736.

It is an arithmetic number, because the mean of its divisors is an integer number (320988).

2^1911561 is an apocalyptic number.

It is an amenable number.

1911561 is a deficient number, since it is larger than the sum of its proper divisors (656343).

1911561 is a wasteful number, since it uses less digits than its factorization.

1911561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4791.

The product of its digits is 270, while the sum is 24.

The square root of 1911561 is about 1382.5921307457. The cubic root of 1911561 is about 124.1069360224.

The spelling of 1911561 in words is "one million, nine hundred eleven thousand, five hundred sixty-one".