42981840 has 280 divisors, whose sum is σ = 165891168. Its totient is φ = 10264320.

The previous prime is 42981839. The next prime is 42981847. The reversal of 42981840 is 4818924.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 42981795 and 42981804.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42981847) by changing a digit.

It is a polite number, since it can be written in 55 ways as a sum of consecutive naturals, for example, 641487 + ... + 641553.

It is a vampire number, since it can be written as 4824 ⋅ 8910 (with its own digits).

Almost surely, 2^42981840 is an apocalyptic number.

42981840 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 42981840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (82945584).

42981840 is an abundant number, since it is smaller than the sum of its proper divisors (122909328).

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

42981840 is a wasteful number, since it uses less digits than its factorization.

42981840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 109 (or 88 counting only the distinct ones).

The product of its (nonzero) digits is 18432, while the sum is 36.

The square root of 42981840 is about 6556.0536910553. The cubic root of 42981840 is about 350.2904799400.

The spelling of 42981840 in words is "forty-two million, nine hundred eighty-one thousand, eight hundred forty".