389994989 has 4 divisors (see below), whose sum is σ = 390035100. Its totient is φ = 389954880.

The previous prime is 389994971. The next prime is 389995003. The reversal of 389994989 is 989499983.

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, and also an emirpimes, since its reverse is a distinct semiprime: 989499983 = 53 ⋅18669811.

It can be written as a sum of positive squares in 2 ways, for example, as 5442889 + 384552100 = 2333^2 + 19610^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-389994989 is a prime.

It is a super-2 number, since 2×389994989² = 304192182890220242, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (389994919) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4787 + ... + 28335.

It is an arithmetic number, because the mean of its divisors is an integer number (97508775).

Almost surely, 2^389994989 is an apocalyptic number.

It is an amenable number.

389994989 is a deficient number, since it is larger than the sum of its proper divisors (40111).

389994989 is a wasteful number, since it uses less digits than its factorization.

389994989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40110.

The product of its digits is 45349632, while the sum is 68.

The square root of 389994989 is about 19748.2907867998. The cubic root of 389994989 is about 730.6112282403.

The spelling of 389994989 in words is "three hundred eighty-nine million, nine hundred ninety-four thousand, nine hundred eighty-nine".