221208240 has 80 divisors (see below), whose sum is σ = 748094976. Its totient is φ = 53625600.

The previous prime is 221208193. The next prime is 221208257. The reversal of 221208240 is 42802122.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (80).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 39256 + ... + 44535.

Almost surely, 2^221208240 is an apocalyptic number.

221208240 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

221208240 is an abundant number, since it is smaller than the sum of its proper divisors (526886736).

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

221208240 is a wasteful number, since it uses less digits than its factorization.

221208240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 83818 (or 83812 counting only the distinct ones).

The product of its (nonzero) digits is 512, while the sum is 21.

The square root of 221208240 is about 14873.0709673557. The cubic root of 221208240 is about 604.7841955082.

It can be divided in two parts, 2212082 and 40, that added together give a palindrome (2212122).

The spelling of 221208240 in words is "two hundred twenty-one million, two hundred eight thousand, two hundred forty".