23121105145 has 4 divisors (see below), whose sum is σ = 27745326180. Its totient is φ = 18496884112.

The previous prime is 23121105109. The next prime is 23121105209. The reversal of 23121105145 is 54150112132.

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 17096085504 + 6025019641 = 130752^2 + 77621^2 .

It is a cyclic number.

It is not a de Polignac number, because 23121105145 - 2³³ = 14531170553 is a prime.

It is a super-2 number, since 2×23121105145² (a number of 22 digits) contains 22 as substring.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 2312110510 + ... + 2312110519.

It is an arithmetic number, because the mean of its divisors is an integer number (6936331545).

Almost surely, 2^23121105145 is an apocalyptic number.

It is an amenable number.

23121105145 is a deficient number, since it is larger than the sum of its proper divisors (4624221035).

23121105145 is an equidigital number, since it uses as much as digits as its factorization.

23121105145 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4624221034.

The product of its (nonzero) digits is 1200, while the sum is 25.

Adding to 23121105145 its reverse (54150112132), we get a palindrome (77271217277).

The spelling of 23121105145 in words is "twenty-three billion, one hundred twenty-one million, one hundred five thousand, one hundred forty-five".