221501400 has 48 divisors (see below), whose sum is σ = 686656200. Its totient is φ = 59066880.

The previous prime is 221501387. The next prime is 221501429. The reversal of 221501400 is 4105122.

221501400 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 221501400.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 183985 + ... + 185184.

Almost surely, 2^221501400 is an apocalyptic number.

221501400 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

221501400 is an abundant number, since it is smaller than the sum of its proper divisors (465154800).

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

221501400 is a wasteful number, since it uses less digits than its factorization.

221501400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 369188 (or 369179 counting only the distinct ones).

The product of its (nonzero) digits is 80, while the sum is 15.

The square root of 221501400 is about 14882.9230999827. The cubic root of 221501400 is about 605.0512444357.

Adding to 221501400 its reverse (4105122), we get a palindrome (225606522).

The spelling of 221501400 in words is "two hundred twenty-one million, five hundred one thousand, four hundred".