42109609 has 2 divisors, whose sum is σ = 42109610. Its totient is φ = 42109608.

The previous prime is 42109601. The next prime is 42109693. The reversal of 42109609 is 90690124.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 24970009 + 17139600 = 4997^2 + 4140^2 .

It is a cyclic number.

It is not a de Polignac number, because 42109609 - 2³ = 42109601 is a prime.

It is a Chen prime.

It is equal to p_2553862 and since 42109609 and 2553862 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (42109601) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21054804 + 21054805.

It is an arithmetic number, because the mean of its divisors is an integer number (21054805).

Almost surely, 2^42109609 is an apocalyptic number.

It is an amenable number.

42109609 is a deficient number, since it is larger than the sum of its proper divisors (1).

42109609 is an equidigital number, since it uses as much as digits as its factorization.

42109609 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3888, while the sum is 31.

The square root of 42109609 is about 6489.1917062143. The cubic root of 42109609 is about 347.9047857935.

The spelling of 42109609 in words is "forty-two million, one hundred nine thousand, six hundred nine".