3640657 has 4 divisors (see below), whose sum is σ = 3649536. Its totient is φ = 3631780.

The previous prime is 3640649. The next prime is 3640661. The reversal of 3640657 is 7560463.

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.

It is a cyclic number.

It is not a de Polignac number, because 3640657 - 2³ = 3640649 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a d-powerful number, because it can be written as 3³ + 6⁵ + 4³ + 0 + 6⁸ + 5⁹ + 7² .

It is a Duffinian number.

3640657 is a lucky number.

It is a plaindrome in base 14.

It is not an unprimeable number, because it can be changed into a prime (3640697) 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, 3793 + ... + 4654.

It is an arithmetic number, because the mean of its divisors is an integer number (912384).

Almost surely, 2^3640657 is an apocalyptic number.

It is an amenable number.

3640657 is a deficient number, since it is larger than the sum of its proper divisors (8879).

3640657 is an equidigital number, since it uses as much as digits as its factorization.

3640657 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8878.

The product of its (nonzero) digits is 15120, while the sum is 31.

The square root of 3640657 is about 1908.0505758496. The cubic root of 3640657 is about 153.8366880650.

It can be divided in two parts, 36406 and 57, that added together give a palindrome (36463).

The spelling of 3640657 in words is "three million, six hundred forty thousand, six hundred fifty-seven".