66172438 has 16 divisors (see below), whose sum is σ = 100576080. Its totient is φ = 32649696.

The previous prime is 66172429. The next prime is 66172439. The reversal of 66172438 is 83427166.

It is a junction number, because it is equal to n+sod(n) for n = 66172397 and 66172406.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66172439) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 79408 + ... + 80236.

It is an arithmetic number, because the mean of its divisors is an integer number (6286005).

Almost surely, 2^66172438 is an apocalyptic number.

66172438 is a deficient number, since it is larger than the sum of its proper divisors (34403642).

66172438 is a wasteful number, since it uses less digits than its factorization.

66172438 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1311.

The product of its digits is 48384, while the sum is 37.

The square root of 66172438 is about 8134.6443069135. The cubic root of 66172438 is about 404.4756471776.

The spelling of 66172438 in words is "sixty-six million, one hundred seventy-two thousand, four hundred thirty-eight".