221690240 has 32 divisors (see below), whose sum is σ = 529979760. Its totient is φ = 88675840.

The previous prime is 221690237. The next prime is 221690257. The reversal of 221690240 is 42096122.

It is a tau number, because it is divible by the number of its divisors (32).

It is a super-2 number, since 2×221690240² = 98293125022515200, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 172556 + ... + 173835.

Almost surely, 2^221690240 is an apocalyptic number.

221690240 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

221690240 is an abundant number, since it is smaller than the sum of its proper divisors (308289520).

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

221690240 is an equidigital number, since it uses as much as digits as its factorization.

221690240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 346410 (or 346398 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 26.

The square root of 221690240 is about 14889.2659322077. The cubic root of 221690240 is about 605.2231401473.

The spelling of 221690240 in words is "two hundred twenty-one million, six hundred ninety thousand, two hundred forty".