42172779 has 16 divisors (see below), whose sum is σ = 61453440. Its totient is φ = 25512960.

The previous prime is 42172759. The next prime is 42172783. The reversal of 42172779 is 97727124.

It is not a de Polignac number, because 42172779 - 2⁸ = 42172523 is a prime.

It is not an unprimeable number, because it can be changed into a prime (42172759) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 29227 + ... + 30635.

It is an arithmetic number, because the mean of its divisors is an integer number (3840840).

Almost surely, 2^42172779 is an apocalyptic number.

42172779 is a deficient number, since it is larger than the sum of its proper divisors (19280661).

42172779 is a wasteful number, since it uses less digits than its factorization.

42172779 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2330.

The product of its digits is 49392, while the sum is 39.

The square root of 42172779 is about 6494.0572064003. The cubic root of 42172779 is about 348.0786666523.

It can be divided in two parts, 4217 and 2779, that added together give a palindrome (6996).

The spelling of 42172779 in words is "forty-two million, one hundred seventy-two thousand, seven hundred seventy-nine".