42918021 has 24 divisors (see below), whose sum is σ = 64157184. Its totient is φ = 27627840.

The previous prime is 42918019. The next prime is 42918037. The reversal of 42918021 is 12081924.

It is not a de Polignac number, because 42918021 - 2¹ = 42918019 is a prime.

It is a plaindrome in base 12.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42918041) by changing a digit.

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 23 ways as a sum of consecutive naturals, for example, 38940 + ... + 40026.

It is an arithmetic number, because the mean of its divisors is an integer number (2673216).

Almost surely, 2^42918021 is an apocalyptic number.

42918021 is a gapful number since it is divisible by the number (41) formed by its first and last digit.

It is an amenable number.

42918021 is a deficient number, since it is larger than the sum of its proper divisors (21239163).

42918021 is a wasteful number, since it uses less digits than its factorization.

42918021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1241 (or 1238 counting only the distinct ones).

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

The square root of 42918021 is about 6551.1847020215. The cubic root of 42918021 is about 350.1170248132.

Adding to 42918021 its reverse (12081924), we get a palindrome (54999945).

It can be divided in two parts, 429180 and 21, that added together give a triangular number (429201 = T₉₂₆).

The spelling of 42918021 in words is "forty-two million, nine hundred eighteen thousand, twenty-one".