221400216 has 56 divisors (see below), whose sum is σ = 622419780. Its totient is φ = 73798128.

The previous prime is 221400211. The next prime is 221400229. The reversal of 221400216 is 612004122.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221400211) by changing a digit.

It is a polite number, since it can be written in 13 ways as a sum of consecutive naturals, for example, 13150 + ... + 24813.

Almost surely, 2^221400216 is an apocalyptic number.

It is an amenable number.

221400216 is an abundant number, since it is smaller than the sum of its proper divisors (401019564).

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

221400216 is an equidigital number, since it uses as much as digits as its factorization.

221400216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 37987 (or 37968 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 18.

The square root of 221400216 is about 14879.5233794635. The cubic root of 221400216 is about 604.9590993000.

Adding to 221400216 its reverse (612004122), we get a palindrome (833404338).

The spelling of 221400216 in words is "two hundred twenty-one million, four hundred thousand, two hundred sixteen".