221396400 has 180 divisors, whose sum is σ = 778064040. Its totient is φ = 58291200.

The previous prime is 221396393. The next prime is 221396401. The reversal of 221396400 is 4693122.

221396400 is a `hidden beast` number, since 2 + 2 + 13 + 9 + 640 + 0 = 666.

221396400 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (180).

It is not an unprimeable number, because it can be changed into a prime (221396401) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 320055 + ... + 320745.

It is an arithmetic number, because the mean of its divisors is an integer number (4322578).

Almost surely, 2^221396400 is an apocalyptic number.

221396400 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 221396400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (389032020).

221396400 is an abundant number, since it is smaller than the sum of its proper divisors (556667640).

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

221396400 is a wasteful number, since it uses less digits than its factorization.

221396400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 804 (or 790 counting only the distinct ones).

The product of its (nonzero) digits is 2592, while the sum is 27.

The square root of 221396400 is about 14879.3951489972. The cubic root of 221396400 is about 604.9556236376.

The spelling of 221396400 in words is "two hundred twenty-one million, three hundred ninety-six thousand, four hundred".