7748921 has 2 divisors, whose sum is σ = 7748922. Its totient is φ = 7748920.

The previous prime is 7748911. The next prime is 7748927. The reversal of 7748921 is 1298477.

7748921 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 6451600 + 1297321 = 2540^2 + 1139^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-7748921 is a prime.

It is not a weakly prime, because it can be changed into another prime (7748927) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3874460 + 3874461.

It is an arithmetic number, because the mean of its divisors is an integer number (3874461).

Almost surely, 2^7748921 is an apocalyptic number.

It is an amenable number.

7748921 is a deficient number, since it is larger than the sum of its proper divisors (1).

7748921 is an equidigital number, since it uses as much as digits as its factorization.

7748921 is an evil number, because the sum of its binary digits is even.

The product of its digits is 28224, while the sum is 38.

The square root of 7748921 is about 2783.6883805484. The cubic root of 7748921 is about 197.8853960469.

The spelling of 7748921 in words is "seven million, seven hundred forty-eight thousand, nine hundred twenty-one".