3609991 has 16 divisors (see below), whose sum is σ = 4543488. Its totient is φ = 2786400.

The previous prime is 3609973. The next prime is 3609997. The reversal of 3609991 is 1999063.

It is a cyclic number.

It is not a de Polignac number, because 3609991 - 2⁵ = 3609959 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 3609991.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3609997) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 13186 + ... + 13456.

It is an arithmetic number, because the mean of its divisors is an integer number (283968).

Almost surely, 2^3609991 is an apocalyptic number.

3609991 is a deficient number, since it is larger than the sum of its proper divisors (933497).

3609991 is a wasteful number, since it uses less digits than its factorization.

3609991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 462.

The product of its (nonzero) digits is 13122, while the sum is 37.

The square root of 3609991 is about 1899.9976315775. The cubic root of 3609991 is about 153.4035369555.

The spelling of 3609991 in words is "three million, six hundred nine thousand, nine hundred ninety-one".