400391728 has 40 divisors (see below), whose sum is σ = 883086336. Its totient is φ = 174081600.

The previous prime is 400391723. The next prime is 400391737. The reversal of 400391728 is 827193004.

It is a junction number, because it is equal to n+sod(n) for n = 400391693 and 400391702.

It is not an unprimeable number, because it can be changed into a prime (400391723) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 45408 + ... + 53503.

Almost surely, 2^400391728 is an apocalyptic number.

It is an amenable number.

400391728 is an abundant number, since it is smaller than the sum of its proper divisors (482694608).

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

400391728 is a wasteful number, since it uses less digits than its factorization.

400391728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 98953 (or 98947 counting only the distinct ones).

The product of its (nonzero) digits is 12096, while the sum is 34.

The square root of 400391728 is about 20009.7908035042. The cubic root of 400391728 is about 737.0467443029.

The spelling of 400391728 in words is "four hundred million, three hundred ninety-one thousand, seven hundred twenty-eight".