3911561 has 4 divisors (see below), whose sum is σ = 3924372. Its totient is φ = 3898752.

The previous prime is 3911543. The next prime is 3911563. The reversal of 3911561 is 1651193.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 739600 + 3171961 = 860^2 + 1781^2 .

It is a cyclic number.

It is not a de Polignac number, because 3911561 - 2⁶ = 3911497 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 3911561.

It is not an unprimeable number, because it can be changed into a prime (3911563) 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, 5936 + ... + 6561.

It is an arithmetic number, because the mean of its divisors is an integer number (981093).

Almost surely, 2^3911561 is an apocalyptic number.

It is an amenable number.

3911561 is a deficient number, since it is larger than the sum of its proper divisors (12811).

3911561 is a wasteful number, since it uses less digits than its factorization.

3911561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12810.

The product of its digits is 810, while the sum is 26.

The square root of 3911561 is about 1977.7666697566. The cubic root of 3911561 is about 157.5614742810.

The spelling of 3911561 in words is "three million, nine hundred eleven thousand, five hundred sixty-one".