221708340 has 360 divisors, whose sum is σ = 856433760. Its totient is φ = 48009024.

The previous prime is 221708309. The next prime is 221708369. The reversal of 221708340 is 43807122.

It is a hoax number, since the sum of its digits (27) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 119 ways as a sum of consecutive naturals, for example, 11668851 + ... + 11668869.

Almost surely, 2^221708340 is an apocalyptic number.

221708340 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 221708340, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (428216880).

221708340 is an abundant number, since it is smaller than the sum of its proper divisors (634725420).

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

221708340 is an equidigital number, since it uses as much as digits as its factorization.

221708340 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 71 (or 36 counting only the distinct ones).

The product of its (nonzero) digits is 2688, while the sum is 27.

The square root of 221708340 is about 14889.8737402303. The cubic root of 221708340 is about 605.2396109382.

The spelling of 221708340 in words is "two hundred twenty-one million, seven hundred eight thousand, three hundred forty".