394401280 has 160 divisors (see below), whose sum is σ = 1164550464. Its totient is φ = 124747776.

The previous prime is 394401277. The next prime is 394401281. The reversal of 394401280 is 82104493.

It is a tau number, because it is divible by the number of its divisors (160).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (394401281) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 232114 + ... + 233806.

Almost surely, 2^394401280 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 394401280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (582275232).

394401280 is an abundant number, since it is smaller than the sum of its proper divisors (770149184).

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

394401280 is a wasteful number, since it uses less digits than its factorization.

394401280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1736 (or 1720 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 31.

The square root of 394401280 is about 19859.5387660439. The cubic root of 394401280 is about 733.3524916942.

The spelling of 394401280 in words is "three hundred ninety-four million, four hundred one thousand, two hundred eighty".