220631400 has 216 divisors, whose sum is σ = 815240790. Its totient is φ = 53433600.

The previous prime is 220631399. The next prime is 220631417. The reversal of 220631400 is 4136022.

It is a happy number.

It can be written as a sum of positive squares in 3 ways, for example, as 84162276 + 136469124 = 9174^2 + 11682^2 .

It is a Harshad number since it is a multiple of its sum of digits (18).

It is an unprimeable number.

It is a polite number, since it can be written in 53 ways as a sum of consecutive naturals, for example, 217294 + ... + 218306.

Almost surely, 2^220631400 is an apocalyptic number.

220631400 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 220631400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (407620395).

220631400 is an abundant number, since it is smaller than the sum of its proper divisors (594609390).

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

220631400 is a wasteful number, since it uses less digits than its factorization.

220631400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1057 (or 1034 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 18.

The square root of 220631400 is about 14853.6662141035. Note that the first 3 decimals coincide. The cubic root of 220631400 is about 604.2580436239.

Adding to 220631400 its reverse (4136022), we get a palindrome (224767422).

The spelling of 220631400 in words is "two hundred twenty million, six hundred thirty-one thousand, four hundred".