221118640 has 40 divisors (see below), whose sum is σ = 520310448. Its totient is φ = 87379200.

The previous prime is 221118571. The next prime is 221118641. The reversal of 221118640 is 46811122.

It is a tau number, because it is divible by the number of its divisors (40).

It is not an unprimeable number, because it can be changed into a prime (221118641) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10011 + ... + 23290.

Almost surely, 2^221118640 is an apocalyptic number.

221118640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

221118640 is an abundant number, since it is smaller than the sum of its proper divisors (299191808).

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

221118640 is a wasteful number, since it uses less digits than its factorization.

221118640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33397 (or 33391 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 25.

The square root of 221118640 is about 14870.0585069461. The cubic root of 221118640 is about 604.7025288971.

Adding to 221118640 its reverse (46811122), we get a palindrome (267929762).

The spelling of 221118640 in words is "two hundred twenty-one million, one hundred eighteen thousand, six hundred forty".