235721 has 4 divisors (see below), whose sum is σ = 238032. Its totient is φ = 233412.

The previous prime is 235699. The next prime is 235723. The reversal of 235721 is 127532.

235721 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 a de Polignac number, because none of the positive numbers 2^k-235721 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 235693 and 235702.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 235721.

It is not an unprimeable number, because it can be changed into a prime (235723) 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, 995 + ... + 1208.

It is an arithmetic number, because the mean of its divisors is an integer number (59508).

2²³⁵⁷²¹ is an apocalyptic number.

It is an amenable number.

235721 is a deficient number, since it is larger than the sum of its proper divisors (2311).

235721 is a wasteful number, since it uses less digits than its factorization.

235721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2310.

The product of its digits is 420, while the sum is 20.

The square root of 235721 is about 485.5110709345. The cubic root of 235721 is about 61.7731040646.

The spelling of 235721 in words is "two hundred thirty-five thousand, seven hundred twenty-one".