394021289 has 4 divisors (see below), whose sum is σ = 407608260. Its totient is φ = 380434320.

The previous prime is 394021283. The next prime is 394021319. The reversal of 394021289 is 982120493.

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 299290000 + 94731289 = 17300^2 + 9733^2 .

It is a cyclic number.

It is not a de Polignac number, because 394021289 - 2²⁴ = 377244073 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (394021283) 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, 6793442 + ... + 6793499.

It is an arithmetic number, because the mean of its divisors is an integer number (101902065).

Almost surely, 2^394021289 is an apocalyptic number.

It is an amenable number.

394021289 is a deficient number, since it is larger than the sum of its proper divisors (13586971).

394021289 is a wasteful number, since it uses less digits than its factorization.

394021289 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13586970.

The product of its (nonzero) digits is 31104, while the sum is 38.

The square root of 394021289 is about 19849.9694961982. The cubic root of 394021289 is about 733.1168967101.

The spelling of 394021289 in words is "three hundred ninety-four million, twenty-one thousand, two hundred eighty-nine".