221550400 has 42 divisors (see below), whose sum is σ = 545156390. Its totient is φ = 88619520.

The previous prime is 221550391. The next prime is 221550403. The reversal of 221550400 is 4055122.

221550400 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 3 ways, for example, as 8156736 + 213393664 = 2856^2 + 14608^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221550403) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 67635 + ... + 70834.

Almost surely, 2^221550400 is an apocalyptic number.

221550400 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

221550400 is an abundant number, since it is smaller than the sum of its proper divisors (323605990).

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

221550400 is a wasteful number, since it uses less digits than its factorization.

221550400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 138491 (or 138476 counting only the distinct ones).

The product of its (nonzero) digits is 400, while the sum is 19.

The square root of 221550400 is about 14884.5691909440. The cubic root of 221550400 is about 605.0958571335.

The spelling of 221550400 in words is "two hundred twenty-one million, five hundred fifty thousand, four hundred".