3690721 has 2 divisors, whose sum is σ = 3690722. Its totient is φ = 3690720.

The previous prime is 3690703. The next prime is 3690727. The reversal of 3690721 is 1270963.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 3474496 + 216225 = 1864^2 + 465^2 .

It is a cyclic number.

It is not a de Polignac number, because 3690721 - 2⁵ = 3690689 is a prime.

It is a Chen prime.

It is an alternating number because its digits alternate between odd and even.

It is a self number, because there is not a number n which added to its sum of digits gives 3690721.

It is not a weakly prime, because it can be changed into another prime (3690727) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1845360 + 1845361.

It is an arithmetic number, because the mean of its divisors is an integer number (1845361).

Almost surely, 2^3690721 is an apocalyptic number.

It is an amenable number.

3690721 is a deficient number, since it is larger than the sum of its proper divisors (1).

3690721 is an equidigital number, since it uses as much as digits as its factorization.

3690721 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2268, while the sum is 28.

The square root of 3690721 is about 1921.1249308673. The cubic root of 3690721 is about 154.5386350247.

The spelling of 3690721 in words is "three million, six hundred ninety thousand, seven hundred twenty-one".