235840021 has 4 divisors (see below), whose sum is σ = 235960000. Its totient is φ = 235720044.

The previous prime is 235840009. The next prime is 235840039. The reversal of 235840021 is 120048532.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 235840021 - 2⁷ = 235839893 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 (235840081) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 56991 + ... + 60988.

It is an arithmetic number, because the mean of its divisors is an integer number (58990000).

Almost surely, 2^235840021 is an apocalyptic number.

It is an amenable number.

235840021 is a deficient number, since it is larger than the sum of its proper divisors (119979).

235840021 is a wasteful number, since it uses less digits than its factorization.

235840021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 119978.

The product of its (nonzero) digits is 1920, while the sum is 25.

The square root of 235840021 is about 15357.0837400856. The cubic root of 235840021 is about 617.8349920617.

Adding to 235840021 its reverse (120048532), we get a palindrome (355888553).

The spelling of 235840021 in words is "two hundred thirty-five million, eight hundred forty thousand, twenty-one".