391620400 has 90 divisors (see below), whose sum is σ = 994769540. Its totient is φ = 147749760.

The previous prime is 391620373. The next prime is 391620409. The reversal of 391620400 is 4026193.

It is a Harshad number since it is a multiple of its sum of digits (25).

It is not an unprimeable number, because it can be changed into a prime (391620409) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 1725087 + ... + 1725313.

Almost surely, 2^391620400 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 391620400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (497384770).

391620400 is an abundant number, since it is smaller than the sum of its proper divisors (603149140).

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

391620400 is a wasteful number, since it uses less digits than its factorization.

391620400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 491 (or 253 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 25.

The square root of 391620400 is about 19789.4012036747. The cubic root of 391620400 is about 731.6248288981.

Adding to 391620400 its reverse (4026193), we get a palindrome (395646593).

The spelling of 391620400 in words is "three hundred ninety-one million, six hundred twenty thousand, four hundred".