7636721 has 2 divisors, whose sum is σ = 7636722. Its totient is φ = 7636720.

The previous prime is 7636709. The next prime is 7636751. The reversal of 7636721 is 1276367.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 6964321 + 672400 = 2639^2 + 820^2 .

It is a cyclic number.

It is not a de Polignac number, because 7636721 - 2¹⁰ = 7635697 is a prime.

It is an Ulam number.

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

It is not a weakly prime, because it can be changed into another prime (7636751) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3818360 + 3818361.

It is an arithmetic number, because the mean of its divisors is an integer number (3818361).

Almost surely, 2^7636721 is an apocalyptic number.

It is an amenable number.

7636721 is a deficient number, since it is larger than the sum of its proper divisors (1).

7636721 is an equidigital number, since it uses as much as digits as its factorization.

7636721 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 7636721 is about 2763.4617782774. The cubic root of 7636721 is about 196.9256592906.

The spelling of 7636721 in words is "seven million, six hundred thirty-six thousand, seven hundred twenty-one".