394451840 has 128 divisors (see below), whose sum is σ = 996433920. Its totient is φ = 149022720.

The previous prime is 394451809. The next prime is 394451887. The reversal of 394451840 is 48154493.

It is a tau number, because it is divible by the number of its divisors (128).

It is a Smith number, since the sum of its digits (38) coincides with the sum of the digits of its prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 394451794 and 394451803.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1869335 + ... + 1869545.

It is an arithmetic number, because the mean of its divisors is an integer number (7784640).

Almost surely, 2^394451840 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 394451840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (498216960).

394451840 is an abundant number, since it is smaller than the sum of its proper divisors (601982080).

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

394451840 is a wasteful number, since it uses less digits than its factorization.

394451840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 380 (or 368 counting only the distinct ones).

The product of its (nonzero) digits is 69120, while the sum is 38.

The square root of 394451840 is about 19860.8116651863. The cubic root of 394451840 is about 733.3838275608.

The spelling of 394451840 in words is "three hundred ninety-four million, four hundred fifty-one thousand, eight hundred forty".