400640600 has 48 divisors (see below), whose sum is σ = 943317600. Its totient is φ = 158221440.

The previous prime is 400640573. The next prime is 400640609. The reversal of 400640600 is 6046004.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (400640609) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3122 + ... + 28478.

It is an arithmetic number, because the mean of its divisors is an integer number (19652450).

Almost surely, 2^400640600 is an apocalyptic number.

400640600 is a gapful number since it is divisible by the number (40) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 400640600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (471658800).

400640600 is an abundant number, since it is smaller than the sum of its proper divisors (542677000).

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

400640600 is a wasteful number, since it uses less digits than its factorization.

400640600 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25452 (or 25443 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 20.

The square root of 400640600 is about 20016.0085931237. The cubic root of 400640600 is about 737.1994217041.

Adding to 400640600 its reverse (6046004), we get a palindrome (406686604).

The spelling of 400640600 in words is "four hundred million, six hundred forty thousand, six hundred".