42161665 has 32 divisors (see below), whose sum is σ = 65560320. Its totient is φ = 25277184.

The previous prime is 42161641. The next prime is 42161681. The reversal of 42161665 is 56616124.

It is a cyclic number.

It is not a de Polignac number, because 42161665 - 2⁵ = 42161633 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 6207 + ... + 11083.

It is an arithmetic number, because the mean of its divisors is an integer number (2048760).

Almost surely, 2^42161665 is an apocalyptic number.

It is an amenable number.

42161665 is a deficient number, since it is larger than the sum of its proper divisors (23398655).

42161665 is a wasteful number, since it uses less digits than its factorization.

42161665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4921.

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

The square root of 42161665 is about 6493.2014445880. The cubic root of 42161665 is about 348.0480870045.

Adding to 42161665 its reverse (56616124), we get a palindrome (98777789).

The spelling of 42161665 in words is "forty-two million, one hundred sixty-one thousand, six hundred sixty-five".