389950021 has 2 divisors, whose sum is σ = 389950022. Its totient is φ = 389950020.

The previous prime is 389950009. The next prime is 389950061. The reversal of 389950021 is 120059983.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 340402500 + 49547521 = 18450^2 + 7039^2 .

It is an emirp because it is prime and its reverse (120059983) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 389950021 - 2¹⁹ = 389425733 is a prime.

It is a super-2 number, since 2×389950021² = 304122037755800882, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (389950061) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 194975010 + 194975011.

It is an arithmetic number, because the mean of its divisors is an integer number (194975011).

Almost surely, 2^389950021 is an apocalyptic number.

It is an amenable number.

389950021 is a deficient number, since it is larger than the sum of its proper divisors (1).

389950021 is an equidigital number, since it uses as much as digits as its factorization.

389950021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 19440, while the sum is 37.

The square root of 389950021 is about 19747.1522250678. The cubic root of 389950021 is about 730.5831463508.

The spelling of 389950021 in words is "three hundred eighty-nine million, nine hundred fifty thousand, twenty-one".