3667721 has 2 divisors, whose sum is σ = 3667722. Its totient is φ = 3667720.

The previous prime is 3667679. The next prime is 3667723. The reversal of 3667721 is 1277663.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2689600 + 978121 = 1640^2 + 989^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-3667721 is a prime.

Together with 3667723, 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 (3667723) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1833860 + 1833861.

It is an arithmetic number, because the mean of its divisors is an integer number (1833861).

Almost surely, 2^3667721 is an apocalyptic number.

It is an amenable number.

3667721 is a deficient number, since it is larger than the sum of its proper divisors (1).

3667721 is an equidigital number, since it uses as much as digits as its factorization.

3667721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 10584, while the sum is 32.

The square root of 3667721 is about 1915.1294995378. The cubic root of 3667721 is about 154.2169456004.

The spelling of 3667721 in words is "three million, six hundred sixty-seven thousand, seven hundred twenty-one".