23721389 has 4 divisors (see below), whose sum is σ = 23820060. Its totient is φ = 23622720.

The previous prime is 23721377. The next prime is 23721407. The reversal of 23721389 is 98312732.

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 17556100 + 6165289 = 4190^2 + 2483^2 .

It is a cyclic number.

It is not a de Polignac number, because 23721389 - 2¹² = 23717293 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 (23721359) 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, 48974 + ... + 49455.

It is an arithmetic number, because the mean of its divisors is an integer number (5955015).

Almost surely, 2^23721389 is an apocalyptic number.

It is an amenable number.

23721389 is a deficient number, since it is larger than the sum of its proper divisors (98671).

23721389 is an equidigital number, since it uses as much as digits as its factorization.

23721389 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 98670.

The product of its digits is 18144, while the sum is 35.

The square root of 23721389 is about 4870.4608611506. The cubic root of 23721389 is about 287.3293818157.

The spelling of 23721389 in words is "twenty-three million, seven hundred twenty-one thousand, three hundred eighty-nine".