240509861 has 2 divisors, whose sum is σ = 240509862. Its totient is φ = 240509860.

The previous prime is 240509839. The next prime is 240509887. The reversal of 240509861 is 168905042.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 237930625 + 2579236 = 15425^2 + 1606^2 .

It is a cyclic number.

It is not a de Polignac number, because 240509861 - 2¹⁰ = 240508837 is a prime.

It is a super-3 number, since 3×240509861³ (a number of 26 digits) contains 333 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (240509821) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 120254930 + 120254931.

It is an arithmetic number, because the mean of its divisors is an integer number (120254931).

Almost surely, 2^240509861 is an apocalyptic number.

It is an amenable number.

240509861 is a deficient number, since it is larger than the sum of its proper divisors (1).

240509861 is an equidigital number, since it uses as much as digits as its factorization.

240509861 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 17280, while the sum is 35.

The square root of 240509861 is about 15508.3803474122. The cubic root of 240509861 is about 621.8862612238.

The spelling of 240509861 in words is "two hundred forty million, five hundred nine thousand, eight hundred sixty-one".