7720399 has 2 divisors, whose sum is σ = 7720400. Its totient is φ = 7720398.

The previous prime is 7720393. The next prime is 7720429. The reversal of 7720399 is 9930277.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 7720399 - 2¹³ = 7712207 is a prime.

7720399 is a lucky number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (7720393) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3860199 + 3860200.

It is an arithmetic number, because the mean of its divisors is an integer number (3860200).

Almost surely, 2^7720399 is an apocalyptic number.

7720399 is a deficient number, since it is larger than the sum of its proper divisors (1).

7720399 is an equidigital number, since it uses as much as digits as its factorization.

7720399 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 23814, while the sum is 37.

The square root of 7720399 is about 2778.5605985834. The cubic root of 7720399 is about 197.6423073070.

The spelling of 7720399 in words is "seven million, seven hundred twenty thousand, three hundred ninety-nine".