42018561 has 32 divisors (see below), whose sum is σ = 68208000. Its totient is φ = 25406784.

The previous prime is 42018551. The next prime is 42018583. The reversal of 42018561 is 16581024.

42018561 is a `hidden beast` number, since 420 + 185 + 61 = 666.

It is not a de Polignac number, because 42018561 - 2⁷ = 42018433 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (42018511) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 19695 + ... + 21723.

It is an arithmetic number, because the mean of its divisors is an integer number (2131500).

Almost surely, 2^42018561 is an apocalyptic number.

It is an amenable number.

42018561 is a deficient number, since it is larger than the sum of its proper divisors (26189439).

42018561 is a wasteful number, since it uses less digits than its factorization.

42018561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2110 (or 2104 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 27.

The square root of 42018561 is about 6482.1725524704. The cubic root of 42018561 is about 347.6538621305.

Adding to 42018561 its reverse (16581024), we get a palindrome (58599585).

It can be divided in two parts, 420 and 18561, that added together give a palindrome (18981).

The spelling of 42018561 in words is "forty-two million, eighteen thousand, five hundred sixty-one".