221545700 has 90 divisors (see below), whose sum is σ = 537313266. Its totient is φ = 79015680.

The previous prime is 221545699. The next prime is 221545711. The reversal of 221545700 is 7545122.

It can be written as a sum of positive squares in 3 ways, for example, as 33362176 + 188183524 = 5776^2 + 13718^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 221545700.

It is an unprimeable number.

It is a polite number, since it can be written in 29 ways as a sum of consecutive naturals, for example, 11660291 + ... + 11660309.

Almost surely, 2^221545700 is an apocalyptic number.

221545700 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 221545700, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (268656633).

221545700 is an abundant number, since it is smaller than the sum of its proper divisors (315767566).

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

221545700 is an equidigital number, since it uses as much as digits as its factorization.

221545700 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 107 (or 43 counting only the distinct ones).

The product of its (nonzero) digits is 2800, while the sum is 26.

The square root of 221545700 is about 14884.4113084798. The cubic root of 221545700 is about 605.0915782416.

The spelling of 221545700 in words is "two hundred twenty-one million, five hundred forty-five thousand, seven hundred".