23409820421 has 4 divisors (see below), whose sum is σ = 25210575852. Its totient is φ = 21609064992.

The previous prime is 23409820393. The next prime is 23409820429. The reversal of 23409820421 is 12402890432.

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 1367964196 + 22041856225 = 36986^2 + 148465^2 .

It is a cyclic number.

It is not a de Polignac number, because 23409820421 - 2¹⁰ = 23409819397 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 (23409820429) 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, 900377696 + ... + 900377721.

It is an arithmetic number, because the mean of its divisors is an integer number (6302643963).

Almost surely, 2^23409820421 is an apocalyptic number.

It is an amenable number.

23409820421 is a deficient number, since it is larger than the sum of its proper divisors (1800755431).

23409820421 is a wasteful number, since it uses less digits than its factorization.

23409820421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1800755430.

The product of its (nonzero) digits is 27648, while the sum is 35.

The spelling of 23409820421 in words is "twenty-three billion, four hundred nine million, eight hundred twenty thousand, four hundred twenty-one".