7240921 has 2 divisors, whose sum is σ = 7240922. Its totient is φ = 7240920.

The previous prime is 7240907. The next prime is 7240973. The reversal of 7240921 is 1290427.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 7080921 + 160000 = 2661^2 + 400^2 .

It is an emirp because it is prime and its reverse (1290427) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 7240921 - 2⁵ = 7240889 is a prime.

7240921 is a lucky number.

It is not a weakly prime, because it can be changed into another prime (7240901) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3620460 + 3620461.

It is an arithmetic number, because the mean of its divisors is an integer number (3620461).

Almost surely, 2^7240921 is an apocalyptic number.

It is an amenable number.

7240921 is a deficient number, since it is larger than the sum of its proper divisors (1).

7240921 is an equidigital number, since it uses as much as digits as its factorization.

7240921 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1008, while the sum is 25.

The square root of 7240921 is about 2690.8959474495. The cubic root of 7240921 is about 193.4630081944.

The spelling of 7240921 in words is "seven million, two hundred forty thousand, nine hundred twenty-one".