42172591 has 2 divisors, whose sum is σ = 42172592. Its totient is φ = 42172590.

The previous prime is 42172541. The next prime is 42172607. The reversal of 42172591 is 19527124.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 42172591 - 2⁷ = 42172463 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (42172511) 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 as a sum of consecutive naturals, namely, 21086295 + 21086296.

It is an arithmetic number, because the mean of its divisors is an integer number (21086296).

Almost surely, 2^42172591 is an apocalyptic number.

42172591 is a deficient number, since it is larger than the sum of its proper divisors (1).

42172591 is an equidigital number, since it uses as much as digits as its factorization.

42172591 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5040, while the sum is 31.

The square root of 42172591 is about 6494.0427316118. The cubic root of 42172591 is about 348.0781494238.

The spelling of 42172591 in words is "forty-two million, one hundred seventy-two thousand, five hundred ninety-one".