240921 has 8 divisors (see below), whose sum is σ = 356960. Its totient is φ = 160596.

The previous prime is 240913. The next prime is 240943. The reversal of 240921 is 129042.

240921 = T₃₃ + T₃₄ + ... + T₁₁₃.

It is not a de Polignac number, because 240921 - 2³ = 240913 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 240894 and 240903.

It is not an unprimeable number, because it can be changed into a prime (240421) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4435 + ... + 4488.

It is an arithmetic number, because the mean of its divisors is an integer number (44620).

2²⁴⁰⁹²¹ is an apocalyptic number.

It is an amenable number.

240921 is a deficient number, since it is larger than the sum of its proper divisors (116039).

240921 is an equidigital number, since it uses as much as digits as its factorization.

240921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8932 (or 8926 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

The square root of 240921 is about 490.8370401671. The cubic root of 240921 is about 62.2240420150.

Adding to 240921 its reverse (129042), we get a palindrome (369963).

The spelling of 240921 in words is "two hundred forty thousand, nine hundred twenty-one".