389443981 has 24 divisors (see below), whose sum is σ = 424398744. Its totient is φ = 357033600.

The previous prime is 389443963. The next prime is 389443993. The reversal of 389443981 is 189344983.

It can be written as a sum of positive squares in 4 ways, for example, as 347076900 + 42367081 = 18630^2 + 6509^2 .

It is not a de Polignac number, because 389443981 - 2⁹ = 389443469 is a prime.

It is a super-2 number, since 2×389443981² = 303333228674256722, 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 (389443921) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1976775 + ... + 1976971.

It is an arithmetic number, because the mean of its divisors is an integer number (17683281).

Almost surely, 2^389443981 is an apocalyptic number.

It is an amenable number.

389443981 is a deficient number, since it is larger than the sum of its proper divisors (34954763).

389443981 is a wasteful number, since it uses less digits than its factorization.

389443981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 381 (or 358 counting only the distinct ones).

The product of its digits is 746496, while the sum is 49.

The square root of 389443981 is about 19734.3350787403. The cubic root of 389443981 is about 730.2669824724.

The spelling of 389443981 in words is "three hundred eighty-nine million, four hundred forty-three thousand, nine hundred eighty-one".