394207128 has 128 divisors (see below), whose sum is σ = 1282176000. Its totient is φ = 109866240.

The previous prime is 394207109. The next prime is 394207147. The reversal of 394207128 is 821702493.

It is an interprime number because it is at equal distance from previous prime (394207109) and next prime (394207147).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 394207092 and 394207101.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 58813 + ... + 65171.

It is an arithmetic number, because the mean of its divisors is an integer number (10017000).

Almost surely, 2^394207128 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 394207128, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (641088000).

394207128 is an abundant number, since it is smaller than the sum of its proper divisors (887968872).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

394207128 is a wasteful number, since it uses less digits than its factorization.

394207128 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6422 (or 6412 counting only the distinct ones).

The product of its (nonzero) digits is 24192, while the sum is 36.

The square root of 394207128 is about 19854.6500346896. The cubic root of 394207128 is about 733.2321360817.

The spelling of 394207128 in words is "three hundred ninety-four million, two hundred seven thousand, one hundred twenty-eight".