389963821 has 4 divisors (see below), whose sum is σ = 419961052. Its totient is φ = 359966592.

The previous prime is 389963807. The next prime is 389963837. The reversal of 389963821 is 128369983.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 16933225 + 373030596 = 4115^2 + 19314^2 .

It is a cyclic number.

It is not a de Polignac number, because 389963821 - 2²³ = 381575213 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (389963521) 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, 14998596 + ... + 14998621.

It is an arithmetic number, because the mean of its divisors is an integer number (104990263).

Almost surely, 2^389963821 is an apocalyptic number.

It is an amenable number.

389963821 is a deficient number, since it is larger than the sum of its proper divisors (29997231).

389963821 is a wasteful number, since it uses less digits than its factorization.

389963821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29997230.

The product of its digits is 559872, while the sum is 49.

The square root of 389963821 is about 19747.5016394480. The cubic root of 389963821 is about 730.5917644881.

The spelling of 389963821 in words is "three hundred eighty-nine million, nine hundred sixty-three thousand, eight hundred twenty-one".