42018921 has 36 divisors (see below), whose sum is σ = 71183424. Its totient is φ = 23814000.

The previous prime is 42018913. The next prime is 42018923. The reversal of 42018921 is 12981024.

It is not a de Polignac number, because 42018921 - 2³ = 42018913 is a prime.

It is a hoax number, since the sum of its digits (27) coincides with the sum of the digits of its distinct prime factors.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (42018923) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 66276 + ... + 66906.

Almost surely, 2^42018921 is an apocalyptic number.

It is an amenable number.

42018921 is a deficient number, since it is larger than the sum of its proper divisors (29164503).

42018921 is a wasteful number, since it uses less digits than its factorization.

42018921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 802 (or 792 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 27.

The square root of 42018921 is about 6482.2003208787. The cubic root of 42018921 is about 347.6548549856.

Adding to 42018921 its reverse (12981024), we get a palindrome (54999945).

The spelling of 42018921 in words is "forty-two million, eighteen thousand, nine hundred twenty-one".