66172015 has 16 divisors (see below), whose sum is σ = 97731648. Its totient is φ = 41884416.

The previous prime is 66172013. The next prime is 66172019. The reversal of 66172015 is 51027166.

It is not a de Polignac number, because 66172015 - 2¹ = 66172013 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66172013) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 72262 + ... + 73171.

It is an arithmetic number, because the mean of its divisors is an integer number (6108228).

Almost surely, 2^66172015 is an apocalyptic number.

66172015 is a gapful number since it is divisible by the number (65) formed by its first and last digit.

66172015 is a deficient number, since it is larger than the sum of its proper divisors (31559633).

66172015 is a wasteful number, since it uses less digits than its factorization.

66172015 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 145458.

The product of its (nonzero) digits is 2520, while the sum is 28.

The square root of 66172015 is about 8134.6183069644. The cubic root of 66172015 is about 404.4747853205.

The spelling of 66172015 in words is "sixty-six million, one hundred seventy-two thousand, fifteen".