390423521 has 2 divisors, whose sum is σ = 390423522. Its totient is φ = 390423520.

The previous prime is 390423499. The next prime is 390423529. The reversal of 390423521 is 125324093.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 361950625 + 28472896 = 19025^2 + 5336^2 .

It is a cyclic number.

It is not a de Polignac number, because 390423521 - 2¹⁸ = 390161377 is a prime.

It is not a weakly prime, because it can be changed into another prime (390423529) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 195211760 + 195211761.

It is an arithmetic number, because the mean of its divisors is an integer number (195211761).

Almost surely, 2^390423521 is an apocalyptic number.

It is an amenable number.

390423521 is a deficient number, since it is larger than the sum of its proper divisors (1).

390423521 is an equidigital number, since it uses as much as digits as its factorization.

390423521 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6480, while the sum is 29.

The square root of 390423521 is about 19759.1376583089. The cubic root of 390423521 is about 730.8787322627.

The spelling of 390423521 in words is "three hundred ninety million, four hundred twenty-three thousand, five hundred twenty-one".