3664721 has 2 divisors, whose sum is σ = 3664722. Its totient is φ = 3664720.

The previous prime is 3664711. The next prime is 3664723. The reversal of 3664721 is 1274663.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 3534400 + 130321 = 1880^2 + 361^2 .

It is a cyclic number.

It is not a de Polignac number, because 3664721 - 2⁶ = 3664657 is a prime.

Together with 3664723, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (3664723) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1832360 + 1832361.

It is an arithmetic number, because the mean of its divisors is an integer number (1832361).

Almost surely, 2^3664721 is an apocalyptic number.

It is an amenable number.

3664721 is a deficient number, since it is larger than the sum of its proper divisors (1).

3664721 is an equidigital number, since it uses as much as digits as its factorization.

3664721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6048, while the sum is 29.

The square root of 3664721 is about 1914.3461024590. The cubic root of 3664721 is about 154.1748870546.

The spelling of 3664721 in words is "three million, six hundred sixty-four thousand, seven hundred twenty-one".