7172128405 has 8 divisors (see below), whose sum is σ = 9268596792. Its totient is φ = 5296340928.

The previous prime is 7172128393. The next prime is 7172128409. The reversal of 7172128405 is 5048212717.

It can be written as a sum of positive squares in 4 ways, for example, as 541120644 + 6631007761 = 23262^2 + 81431^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 7172128405 - 2²³ = 7163739797 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7172128409) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 55170154 + ... + 55170283.

It is an arithmetic number, because the mean of its divisors is an integer number (1158574599).

Almost surely, 2^7172128405 is an apocalyptic number.

It is an amenable number.

7172128405 is a deficient number, since it is larger than the sum of its proper divisors (2096468387).

7172128405 is a wasteful number, since it uses less digits than its factorization.

7172128405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 110340455.

The product of its (nonzero) digits is 31360, while the sum is 37.

The square root of 7172128405 is about 84688.4195448232. The cubic root of 7172128405 is about 1928.4839056015.

The spelling of 7172128405 in words is "seven billion, one hundred seventy-two million, one hundred twenty-eight thousand, four hundred five".