42172387 has 4 divisors (see below), whose sum is σ = 42205680. Its totient is φ = 42139096.

The previous prime is 42172373. The next prime is 42172397. The reversal of 42172387 is 78327124.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 42172387 - 2¹⁵ = 42139619 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (42172327) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 14668 + ... + 17305.

It is an arithmetic number, because the mean of its divisors is an integer number (10551420).

Almost surely, 2^42172387 is an apocalyptic number.

42172387 is a deficient number, since it is larger than the sum of its proper divisors (33293).

42172387 is a wasteful number, since it uses less digits than its factorization.

42172387 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33292.

The product of its digits is 18816, while the sum is 34.

The square root of 42172387 is about 6494.0270248899. The cubic root of 42172387 is about 348.0775881742.

The spelling of 42172387 in words is "forty-two million, one hundred seventy-two thousand, three hundred eighty-seven".