221745894400 has 132 divisors (see below), whose sum is σ = 560035692252. Its totient is φ = 87024271360.

The previous prime is 221745894313. The next prime is 221745894449. The reversal of 221745894400 is 4498547122.

221745894400 is nontrivially palindromic in base 7.

It can be written as a sum of positive squares in 6 ways, for example, as 17644340224 + 204101554176 = 132832^2 + 451776^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1275084 + ... + 1438516.

Almost surely, 2^221745894400 is an apocalyptic number.

221745894400 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 221745894400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (280017846126).

221745894400 is an abundant number, since it is smaller than the sum of its proper divisors (338289797852).

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

221745894400 is a wasteful number, since it uses less digits than its factorization.

221745894400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 163516 (or 163493 counting only the distinct ones).

The product of its (nonzero) digits is 645120, while the sum is 46.

The spelling of 221745894400 in words is "two hundred twenty-one billion, seven hundred forty-five million, eight hundred ninety-four thousand, four hundred".