21523430117 has 4 divisors (see below), whose sum is σ = 24598205856. Its totient is φ = 18448654380.

The previous prime is 21523430081. The next prime is 21523430161. The reversal of 21523430117 is 71103432512.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21523430117 - 2⁶ = 21523430053 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21523430117.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21523430167) 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, 1537387859 + ... + 1537387872.

It is an arithmetic number, because the mean of its divisors is an integer number (6149551464).

Almost surely, 2^21523430117 is an apocalyptic number.

It is an amenable number.

21523430117 is a deficient number, since it is larger than the sum of its proper divisors (3074775739).

21523430117 is an equidigital number, since it uses as much as digits as its factorization.

21523430117 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3074775738.

The product of its (nonzero) digits is 5040, while the sum is 29.

Adding to 21523430117 its reverse (71103432512), we get a palindrome (92626862629).

The spelling of 21523430117 in words is "twenty-one billion, five hundred twenty-three million, four hundred thirty thousand, one hundred seventeen".