3640491 has 16 divisors (see below), whose sum is σ = 5447200. Its totient is φ = 2402784.

The previous prime is 3640487. The next prime is 3640493. The reversal of 3640491 is 1940463.

It is not a de Polignac number, because 3640491 - 2² = 3640487 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Duffinian number.

3640491 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (3640493) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2325 + ... + 3561.

It is an arithmetic number, because the mean of its divisors is an integer number (340450).

Almost surely, 2^3640491 is an apocalyptic number.

3640491 is a deficient number, since it is larger than the sum of its proper divisors (1806709).

3640491 is a wasteful number, since it uses less digits than its factorization.

3640491 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1355 (or 1349 counting only the distinct ones).

The product of its (nonzero) digits is 2592, while the sum is 27.

The square root of 3640491 is about 1908.0070754586. The cubic root of 3640491 is about 153.8343499085.

Subtracting from 3640491 its sum of digits (27), we obtain a square (3640464 = 1908²).

The spelling of 3640491 in words is "three million, six hundred forty thousand, four hundred ninety-one".