221166400 has 336 divisors, whose sum is σ = 705510400. Its totient is φ = 67737600.

The previous prime is 221166377. The next prime is 221166401. The reversal of 221166400 is 4661122.

221166400 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a hoax number, since the sum of its digits (22) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221166401) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 7134385 + ... + 7134415.

Almost surely, 2^221166400 is an apocalyptic number.

221166400 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 221166400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (352755200).

221166400 is an abundant number, since it is smaller than the sum of its proper divisors (484344000).

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

221166400 is a wasteful number, since it uses less digits than its factorization.

221166400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 87 (or 58 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 22.

The square root of 221166400 is about 14871.6643318762. The cubic root of 221166400 is about 604.7460628625.

The spelling of 221166400 in words is "two hundred twenty-one million, one hundred sixty-six thousand, four hundred".