3640391 has 2 divisors, whose sum is σ = 3640392. Its totient is φ = 3640390.

The previous prime is 3640379. The next prime is 3640409. The reversal of 3640391 is 1930463.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 3640391 - 2⁶ = 3640327 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 3640391.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (3640331) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1820195 + 1820196.

It is an arithmetic number, because the mean of its divisors is an integer number (1820196).

Almost surely, 2^3640391 is an apocalyptic number.

3640391 is a deficient number, since it is larger than the sum of its proper divisors (1).

3640391 is an equidigital number, since it uses as much as digits as its factorization.

3640391 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1944, while the sum is 26.

The square root of 3640391 is about 1907.9808699251. The cubic root of 3640391 is about 153.8329413461.

The spelling of 3640391 in words is "three million, six hundred forty thousand, three hundred ninety-one".