220400400 has 240 divisors, whose sum is σ = 786021120. Its totient is φ = 52339200.

The previous prime is 220400371. The next prime is 220400417. The reversal of 220400400 is 4004022.

It is a tau number, because it is divible by the number of its divisors (240).

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a super Niven number, because it is divisible the sum of any subset of its (nonzero) digits.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 778659 + ... + 778941.

It is an arithmetic number, because the mean of its divisors is an integer number (3275088).

Almost surely, 2^220400400 is an apocalyptic number.

220400400 is a gapful number since it is divisible by the number (20) 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 220400400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (393010560).

220400400 is an abundant number, since it is smaller than the sum of its proper divisors (565620720).

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

220400400 is a wasteful number, since it uses less digits than its factorization.

220400400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 374 (or 363 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 12.

The square root of 220400400 is about 14845.8883196662. Note that the first 3 decimals coincide. The cubic root of 220400400 is about 604.0470849074.

Adding to 220400400 its reverse (4004022), we get a palindrome (224404422).

It can be divided in two parts, 2 and 20400400, that added together give a palindrome (20400402).

The spelling of 220400400 in words is "two hundred twenty million, four hundred thousand, four hundred".