7888921 has 2 divisors, whose sum is σ = 7888922. Its totient is φ = 7888920.

The previous prime is 7888919. The next prime is 7888981. The reversal of 7888921 is 1298887.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 7485696 + 403225 = 2736^2 + 635^2 .

It is an emirp because it is prime and its reverse (1298887) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 7888921 - 2¹ = 7888919 is a prime.

Together with 7888919, it forms a pair of twin primes.

It is an Ulam number.

It is not a weakly prime, because it can be changed into another prime (7888981) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3944460 + 3944461.

It is an arithmetic number, because the mean of its divisors is an integer number (3944461).

Almost surely, 2^7888921 is an apocalyptic number.

It is an amenable number.

7888921 is a deficient number, since it is larger than the sum of its proper divisors (1).

7888921 is an equidigital number, since it uses as much as digits as its factorization.

7888921 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 64512, while the sum is 43.

The square root of 7888921 is about 2808.7223073846. The cubic root of 7888921 is about 199.0700240932.

The spelling of 7888921 in words is "seven million, eight hundred eighty-eight thousand, nine hundred twenty-one".