393406728 has 128 divisors (see below), whose sum is σ = 1170892800. Its totient is φ = 108576000.

The previous prime is 393406703. The next prime is 393406759. The reversal of 393406728 is 827604393.

It is a Smith number, since the sum of its digits (42) coincides with the sum of the digits of its prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 393406728.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 270403 + ... + 271853.

It is an arithmetic number, because the mean of its divisors is an integer number (9147600).

Almost surely, 2^393406728 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 393406728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (585446400).

393406728 is an abundant number, since it is smaller than the sum of its proper divisors (777486072).

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

393406728 is a wasteful number, since it uses less digits than its factorization.

393406728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1563 (or 1559 counting only the distinct ones).

The product of its (nonzero) digits is 217728, while the sum is 42.

The square root of 393406728 is about 19834.4833055968. The cubic root of 393406728 is about 732.7355471827.

The spelling of 393406728 in words is "three hundred ninety-three million, four hundred six thousand, seven hundred twenty-eight".