3657891 has 4 divisors (see below), whose sum is σ = 4877192. Its totient is φ = 2438592.

The previous prime is 3657887. The next prime is 3657911. The reversal of 3657891 is 1987563.

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

It is not a de Polignac number, because 3657891 - 2² = 3657887 is a prime.

It is a D-number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (3657691) 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, 609646 + ... + 609651.

It is an arithmetic number, because the mean of its divisors is an integer number (1219298).

Almost surely, 2^3657891 is an apocalyptic number.

3657891 is a deficient number, since it is larger than the sum of its proper divisors (1219301).

3657891 is a wasteful number, since it uses less digits than its factorization.

3657891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1219300.

The product of its digits is 45360, while the sum is 39.

The square root of 3657891 is about 1912.5613715643. The cubic root of 3657891 is about 154.0790480780.

It can be divided in two parts, 365 and 7891, that added together give a triangular number (8256 = T₁₂₈).

The spelling of 3657891 in words is "three million, six hundred fifty-seven thousand, eight hundred ninety-one".