390724993 has 2 divisors, whose sum is σ = 390724994. Its totient is φ = 390724992.

The previous prime is 390724931. The next prime is 390725003. The reversal of 390724993 is 399427093.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 358269184 + 32455809 = 18928^2 + 5697^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-390724993 is a prime.

It is not a weakly prime, because it can be changed into another prime (390724913) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 195362496 + 195362497.

It is an arithmetic number, because the mean of its divisors is an integer number (195362497).

Almost surely, 2^390724993 is an apocalyptic number.

It is an amenable number.

390724993 is a deficient number, since it is larger than the sum of its proper divisors (1).

390724993 is an equidigital number, since it uses as much as digits as its factorization.

390724993 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 367416, while the sum is 46.

The square root of 390724993 is about 19766.7648592277. The cubic root of 390724993 is about 731.0668039103.

It can be divided in two parts, 3907 and 24993, that added together give a square (28900 = 170²).

The spelling of 390724993 in words is "three hundred ninety million, seven hundred twenty-four thousand, nine hundred ninety-three".