240221991 has 4 divisors (see below), whose sum is σ = 320295992. Its totient is φ = 160147992.

The previous prime is 240221987. The next prime is 240221999. The reversal of 240221991 is 199122042.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 240221991 - 2² = 240221987 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (240221999) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 40036996 + ... + 40037001.

It is an arithmetic number, because the mean of its divisors is an integer number (80073998).

Almost surely, 2^240221991 is an apocalyptic number.

240221991 is a deficient number, since it is larger than the sum of its proper divisors (80074001).

240221991 is an equidigital number, since it uses as much as digits as its factorization.

240221991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 80074000.

The product of its (nonzero) digits is 2592, while the sum is 30.

The square root of 240221991 is about 15499.0964575358. The cubic root of 240221991 is about 621.6380470484.

The spelling of 240221991 in words is "two hundred forty million, two hundred twenty-one thousand, nine hundred ninety-one".