12172545405 has 64 divisors (see below), whose sum is σ = 23108659200. Its totient is φ = 6065902080.

The previous prime is 12172545401. The next prime is 12172545419. The reversal of 12172545405 is 50454527121.

12172545405 is a `hidden beast` number, since 1 + 2 + 1 + 72 + 545 + 40 + 5 = 666.

It is not a de Polignac number, because 12172545405 - 2² = 12172545401 is a prime.

It is a super-2 number, since 2×12172545405² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 12172545405.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12172545401) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 71217 + ... + 171513.

It is an arithmetic number, because the mean of its divisors is an integer number (361072800).

Almost surely, 2^12172545405 is an apocalyptic number.

12172545405 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

12172545405 is a deficient number, since it is larger than the sum of its proper divisors (10936113795).

12172545405 is a wasteful number, since it uses less digits than its factorization.

12172545405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 100371 (or 100365 counting only the distinct ones).

The product of its (nonzero) digits is 56000, while the sum is 36.

The spelling of 12172545405 in words is "twelve billion, one hundred seventy-two million, five hundred forty-five thousand, four hundred five".