7309921 has 2 divisors, whose sum is σ = 7309922. Its totient is φ = 7309920.

The previous prime is 7309903. The next prime is 7309933. The reversal of 7309921 is 1299037.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 4950625 + 2359296 = 2225^2 + 1536^2 .

It is a cyclic number.

It is not a de Polignac number, because 7309921 - 2¹¹ = 7307873 is a prime.

It is not a weakly prime, because it can be changed into another prime (7309021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3654960 + 3654961.

It is an arithmetic number, because the mean of its divisors is an integer number (3654961).

Almost surely, 2^7309921 is an apocalyptic number.

It is an amenable number.

7309921 is a deficient number, since it is larger than the sum of its proper divisors (1).

7309921 is an equidigital number, since it uses as much as digits as its factorization.

7309921 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3402, while the sum is 31.

The square root of 7309921 is about 2703.6865572769. The cubic root of 7309921 is about 194.0755807819.

The spelling of 7309921 in words is "seven million, three hundred nine thousand, nine hundred twenty-one".