221213240 has 16 divisors (see below), whose sum is σ = 497729880. Its totient is φ = 88485280.

The previous prime is 221213233. The next prime is 221213261. The reversal of 221213240 is 42312122.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2765126 + ... + 2765205.

Almost surely, 2^221213240 is an apocalyptic number.

221213240 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

221213240 is an abundant number, since it is smaller than the sum of its proper divisors (276516640).

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

221213240 is a wasteful number, since it uses less digits than its factorization.

221213240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5530342 (or 5530338 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 17.

The square root of 221213240 is about 14873.2390554311. The cubic root of 221213240 is about 604.7887521470.

Adding to 221213240 its reverse (42312122), we get a palindrome (263525362).

The spelling of 221213240 in words is "two hundred twenty-one million, two hundred thirteen thousand, two hundred forty".