42945840 has 120 divisors (see below), whose sum is σ = 164849568. Its totient is φ = 9815040.

The previous prime is 42945829. The next prime is 42945869. The reversal of 42945840 is 4854924.

It is a tau number, because it is divible by the number of its divisors (120).

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 = 42945795 and 42945804.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 780 + ... + 9300.

Almost surely, 2^42945840 is an apocalyptic number.

42945840 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 42945840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (82424784).

42945840 is an abundant number, since it is smaller than the sum of its proper divisors (121903728).

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

42945840 is a wasteful number, since it uses less digits than its factorization.

42945840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8547 (or 8538 counting only the distinct ones).

The product of its (nonzero) digits is 46080, while the sum is 36.

The square root of 42945840 is about 6553.3075618347. The cubic root of 42945840 is about 350.1926558388.

The spelling of 42945840 in words is "forty-two million, nine hundred forty-five thousand, eight hundred forty".