240645991 has 2 divisors, whose sum is σ = 240645992. Its totient is φ = 240645990.

The previous prime is 240645983. The next prime is 240646013. The reversal of 240645991 is 199546042.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 240645991 - 2³ = 240645983 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (240645191) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 120322995 + 120322996.

It is an arithmetic number, because the mean of its divisors is an integer number (120322996).

Almost surely, 2^240645991 is an apocalyptic number.

240645991 is a deficient number, since it is larger than the sum of its proper divisors (1).

240645991 is an equidigital number, since it uses as much as digits as its factorization.

240645991 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 77760, while the sum is 40.

The square root of 240645991 is about 15512.7686439268. The cubic root of 240645991 is about 622.0035695249.

The spelling of 240645991 in words is "two hundred forty million, six hundred forty-five thousand, nine hundred ninety-one".