42109897 has 2 divisors, whose sum is σ = 42109898. Its totient is φ = 42109896.

The previous prime is 42109891. The next prime is 42109913. The reversal of 42109897 is 79890124.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 23970816 + 18139081 = 4896^2 + 4259^2 .

It is a cyclic number.

It is not a de Polignac number, because 42109897 - 2³ = 42109889 is a prime.

It is not a weakly prime, because it can be changed into another prime (42109891) 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, 21054948 + 21054949.

It is an arithmetic number, because the mean of its divisors is an integer number (21054949).

Almost surely, 2^42109897 is an apocalyptic number.

It is an amenable number.

42109897 is a deficient number, since it is larger than the sum of its proper divisors (1).

42109897 is an equidigital number, since it uses as much as digits as its factorization.

42109897 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 36288, while the sum is 40.

The square root of 42109897 is about 6489.2138969216. The cubic root of 42109897 is about 347.9055789328.

The spelling of 42109897 in words is "forty-two million, one hundred nine thousand, eight hundred ninety-seven".