23706821 has 4 divisors (see below), whose sum is σ = 23941644. Its totient is φ = 23472000.

The previous prime is 23706797. The next prime is 23706853. The reversal of 23706821 is 12860732.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 20376196 + 3330625 = 4514^2 + 1825^2 .

It is a cyclic number.

It is not a de Polignac number, because 23706821 - 2¹⁰ = 23705797 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (23706871) 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, 117260 + ... + 117461.

It is an arithmetic number, because the mean of its divisors is an integer number (5985411).

Almost surely, 2^23706821 is an apocalyptic number.

It is an amenable number.

23706821 is a deficient number, since it is larger than the sum of its proper divisors (234823).

23706821 is a wasteful number, since it uses less digits than its factorization.

23706821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 234822.

The product of its (nonzero) digits is 4032, while the sum is 29.

The square root of 23706821 is about 4868.9650851079. The cubic root of 23706821 is about 287.2705506401.

The spelling of 23706821 in words is "twenty-three million, seven hundred six thousand, eight hundred twenty-one".