23520891209 has 4 divisors (see below), whose sum is σ = 23522728980. Its totient is φ = 23519053440.

The previous prime is 23520891187. The next prime is 23520891311. The reversal of 23520891209 is 90219802532.

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 17279891209 + 6241000000 = 131453^2 + 79000^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-23520891209 is a prime.

It is a super-2 number, since 2×23520891209² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (23520891509) 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, 899552 + ... + 925329.

It is an arithmetic number, because the mean of its divisors is an integer number (5880682245).

Almost surely, 2^23520891209 is an apocalyptic number.

It is an amenable number.

23520891209 is a deficient number, since it is larger than the sum of its proper divisors (1837771).

23520891209 is a wasteful number, since it uses less digits than its factorization.

23520891209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1837770.

The product of its (nonzero) digits is 77760, while the sum is 41.

The spelling of 23520891209 in words is "twenty-three billion, five hundred twenty million, eight hundred ninety-one thousand, two hundred nine".