3609861 has 4 divisors (see below), whose sum is σ = 4813152. Its totient is φ = 2406572.

The previous prime is 3609847. The next prime is 3609863. The reversal of 3609861 is 1689063.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1689063 = 3 ⋅563021.

It is a cyclic number.

It is not a de Polignac number, because 3609861 - 2⁹ = 3609349 is a prime.

It is a D-number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3609863) 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, 601641 + ... + 601646.

It is an arithmetic number, because the mean of its divisors is an integer number (1203288).

Almost surely, 2^3609861 is an apocalyptic number.

It is an amenable number.

3609861 is a deficient number, since it is larger than the sum of its proper divisors (1203291).

3609861 is a wasteful number, since it uses less digits than its factorization.

3609861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1203290.

The product of its (nonzero) digits is 7776, while the sum is 33.

The square root of 3609861 is about 1899.9634207005. The cubic root of 3609861 is about 153.4016955198.

The spelling of 3609861 in words is "three million, six hundred nine thousand, eight hundred sixty-one".