42109645 has 4 divisors (see below), whose sum is σ = 50531580. Its totient is φ = 33687712.

The previous prime is 42109609. The next prime is 42109693. The reversal of 42109645 is 54690124.

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

It can be written as a sum of positive squares in 2 ways, for example, as 12830724 + 29278921 = 3582^2 + 5411^2 .

It is a cyclic number.

It is not a de Polignac number, because 42109645 - 2¹⁵ = 42076877 is a prime.

It is a super-3 number, since 3×42109645³ (a number of 24 digits) contains 333 as substring.

It is a congruent number.

It is an unprimeable number.

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 in 3 ways as a sum of consecutive naturals, for example, 4210960 + ... + 4210969.

It is an arithmetic number, because the mean of its divisors is an integer number (12632895).

Almost surely, 2^42109645 is an apocalyptic number.

It is an amenable number.

42109645 is a deficient number, since it is larger than the sum of its proper divisors (8421935).

42109645 is an equidigital number, since it uses as much as digits as its factorization.

42109645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8421934.

The product of its (nonzero) digits is 8640, while the sum is 31.

The square root of 42109645 is about 6489.1944800568. The cubic root of 42109645 is about 347.9048849362.

Adding to 42109645 its reverse (54690124), we get a palindrome (96799769).

The spelling of 42109645 in words is "forty-two million, one hundred nine thousand, six hundred forty-five".