42123840 has 112 divisors (see below), whose sum is σ = 145938240. Its totient is φ = 10209280.

The previous prime is 42123839. The next prime is 42123857. The reversal of 42123840 is 4832124.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a self number, because there is not a number n which added to its sum of digits gives 42123840.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8566 + ... + 12554.

It is an arithmetic number, because the mean of its divisors is an integer number (1303020).

Almost surely, 2^42123840 is an apocalyptic number.

42123840 is a gapful number since it is divisible by the number (40) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 42123840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (72969120).

42123840 is an abundant number, since it is smaller than the sum of its proper divisors (103814400).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

42123840 is a wasteful number, since it uses less digits than its factorization.

42123840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4020 (or 4010 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 24.

The square root of 42123840 is about 6490.2881291973. The cubic root of 42123840 is about 347.9439730123.

Adding to 42123840 its reverse (4832124), we get a palindrome (46955964).

The spelling of 42123840 in words is "forty-two million, one hundred twenty-three thousand, eight hundred forty".