7638881 has 2 divisors, whose sum is σ = 7638882. Its totient is φ = 7638880.

The previous prime is 7638877. The next prime is 7638889. The reversal of 7638881 is 1888367.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 5107600 + 2531281 = 2260^2 + 1591^2 .

It is a cyclic number.

It is not a de Polignac number, because 7638881 - 2² = 7638877 is a prime.

It is a super-2 number, since 2×7638881² = 116705005864322, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is an Ulam number.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (7638889) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3819440 + 3819441.

It is an arithmetic number, because the mean of its divisors is an integer number (3819441).

Almost surely, 2^7638881 is an apocalyptic number.

It is an amenable number.

7638881 is a deficient number, since it is larger than the sum of its proper divisors (1).

7638881 is an equidigital number, since it uses as much as digits as its factorization.

7638881 is an evil number, because the sum of its binary digits is even.

The product of its digits is 64512, while the sum is 41.

The square root of 7638881 is about 2763.8525648088. The cubic root of 7638881 is about 196.9442239480.

The spelling of 7638881 in words is "seven million, six hundred thirty-eight thousand, eight hundred eighty-one".