390390521 has 2 divisors, whose sum is σ = 390390522. Its totient is φ = 390390520.

The previous prime is 390390493. The next prime is 390390571. The reversal of 390390521 is 125093093.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 385572496 + 4818025 = 19636^2 + 2195^2 .

It is a cyclic number.

It is not a de Polignac number, because 390390521 - 2¹⁴ = 390374137 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (390390571) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 195195260 + 195195261.

It is an arithmetic number, because the mean of its divisors is an integer number (195195261).

Almost surely, 2^390390521 is an apocalyptic number.

It is an amenable number.

390390521 is a deficient number, since it is larger than the sum of its proper divisors (1).

390390521 is an equidigital number, since it uses as much as digits as its factorization.

390390521 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 7290, while the sum is 32.

The square root of 390390521 is about 19758.3025839772. The cubic root of 390390521 is about 730.8581395162.

The spelling of 390390521 in words is "three hundred ninety million, three hundred ninety thousand, five hundred twenty-one".