390561989 has 4 divisors (see below), whose sum is σ = 390608556. Its totient is φ = 390515424.

The previous prime is 390561979. The next prime is 390562001. The reversal of 390561989 is 989165093.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 103530625 + 287031364 = 10175^2 + 16942^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-390561989 is a prime.

It is a super-2 number, since 2×390561989² = 305077334503272242, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (390561979) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6824 + ... + 28769.

It is an arithmetic number, because the mean of its divisors is an integer number (97652139).

Almost surely, 2^390561989 is an apocalyptic number.

It is an amenable number.

390561989 is a deficient number, since it is larger than the sum of its proper divisors (46567).

390561989 is a wasteful number, since it uses less digits than its factorization.

390561989 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 46566.

The product of its (nonzero) digits is 524880, while the sum is 50.

The square root of 390561989 is about 19762.6412455421. The cubic root of 390561989 is about 730.9651267795.

The spelling of 390561989 in words is "three hundred ninety million, five hundred sixty-one thousand, nine hundred eighty-nine".