391636400 has 60 divisors (see below), whose sum is σ = 943040832. Its totient is φ = 156299520.

The previous prime is 391636381. The next prime is 391636403. The reversal of 391636400 is 4636193.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (391636403) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 241994 + ... + 243606.

Almost surely, 2^391636400 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 391636400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (471520416).

391636400 is an abundant number, since it is smaller than the sum of its proper divisors (551404432).

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

391636400 is a wasteful number, since it uses less digits than its factorization.

391636400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2238 (or 2227 counting only the distinct ones).

The product of its (nonzero) digits is 11664, while the sum is 32.

The square root of 391636400 is about 19789.8054563454. The cubic root of 391636400 is about 731.6347924902.

The spelling of 391636400 in words is "three hundred ninety-one million, six hundred thirty-six thousand, four hundred".