23403821 has 12 divisors (see below), whose sum is σ = 27500220. Its totient is φ = 19857600.

The previous prime is 23403773. The next prime is 23403823. The reversal of 23403821 is 12830432.

It can be written as a sum of positive squares in 2 ways, for example, as 11055625 + 12348196 = 3325^2 + 3514^2 .

It is not a de Polignac number, because 23403821 - 2¹⁴ = 23387437 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 (23403823) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2585 + ... + 7313.

It is an arithmetic number, because the mean of its divisors is an integer number (2291685).

Almost surely, 2^23403821 is an apocalyptic number.

It is an amenable number.

23403821 is a deficient number, since it is larger than the sum of its proper divisors (4096399).

23403821 is a wasteful number, since it uses less digits than its factorization.

23403821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4844 (or 4837 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 23.

The square root of 23403821 is about 4837.7495801250. The cubic root of 23403821 is about 286.0414181951.

The spelling of 23403821 in words is "twenty-three million, four hundred three thousand, eight hundred twenty-one".