7688921 has 2 divisors, whose sum is σ = 7688922. Its totient is φ = 7688920.

The previous prime is 7688893. The next prime is 7688929. The reversal of 7688921 is 1298867.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 7398400 + 290521 = 2720^2 + 539^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-7688921 is a prime.

It is a super-2 number, since 2×7688921² = 118239012288482, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (7688929) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3844460 + 3844461.

It is an arithmetic number, because the mean of its divisors is an integer number (3844461).

Almost surely, 2^7688921 is an apocalyptic number.

It is an amenable number.

7688921 is a deficient number, since it is larger than the sum of its proper divisors (1).

7688921 is an equidigital number, since it uses as much as digits as its factorization.

7688921 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 48384, while the sum is 41.

The square root of 7688921 is about 2772.8903692717. The cubic root of 7688921 is about 197.3733290182.

The spelling of 7688921 in words is "seven million, six hundred eighty-eight thousand, nine hundred twenty-one".