390228989 has 2 divisors, whose sum is σ = 390228990. Its totient is φ = 390228988.

The previous prime is 390228929. The next prime is 390229001. The reversal of 390228989 is 989822093.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 357852889 + 32376100 = 18917^2 + 5690^2 .

It is a cyclic number.

It is not a de Polignac number, because 390228989 - 2¹² = 390224893 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (390228919) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 195114494 + 195114495.

It is an arithmetic number, because the mean of its divisors is an integer number (195114495).

Almost surely, 2^390228989 is an apocalyptic number.

It is an amenable number.

390228989 is a deficient number, since it is larger than the sum of its proper divisors (1).

390228989 is an equidigital number, since it uses as much as digits as its factorization.

390228989 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 559872, while the sum is 50.

The square root of 390228989 is about 19754.2144617294. The cubic root of 390228989 is about 730.7573231480.

The spelling of 390228989 in words is "three hundred ninety million, two hundred twenty-eight thousand, nine hundred eighty-nine".