42189997 has 2 divisors, whose sum is σ = 42189998. Its totient is φ = 42189996.

The previous prime is 42189989. The next prime is 42190021. The reversal of 42189997 is 79998124.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 42068196 + 121801 = 6486^2 + 349^2 .

It is a cyclic number.

It is not a de Polignac number, because 42189997 - 2³ = 42189989 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 42189997.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (42189907) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21094998 + 21094999.

It is an arithmetic number, because the mean of its divisors is an integer number (21094999).

Almost surely, 2^42189997 is an apocalyptic number.

It is an amenable number.

42189997 is a deficient number, since it is larger than the sum of its proper divisors (1).

42189997 is an equidigital number, since it uses as much as digits as its factorization.

42189997 is an evil number, because the sum of its binary digits is even.

The product of its digits is 326592, while the sum is 49.

The square root of 42189997 is about 6495.3827446887. The cubic root of 42189997 is about 348.1260305616.

The spelling of 42189997 in words is "forty-two million, one hundred eighty-nine thousand, nine hundred ninety-seven".