42066640 has 80 divisors (see below), whose sum is σ = 121956480. Its totient is φ = 13109760.

The previous prime is 42066593. The next prime is 42066643. The reversal of 42066640 is 4666024.

It is a tau number, because it is divible by the number of its divisors (80).

It is a Harshad number since it is a multiple of its sum of digits (28).

It is a junction number, because it is equal to n+sod(n) for n = 42066599 and 42066608.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42066643) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2746 + ... + 9574.

It is an arithmetic number, because the mean of its divisors is an integer number (1524456).

Almost surely, 2^42066640 is an apocalyptic number.

42066640 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 42066640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (60978240).

42066640 is an abundant number, since it is smaller than the sum of its proper divisors (79889840).

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

42066640 is a wasteful number, since it uses less digits than its factorization.

42066640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6860 (or 6854 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 28.

The square root of 42066640 is about 6485.8800482278. The cubic root of 42066640 is about 347.7864105286.

The spelling of 42066640 in words is "forty-two million, sixty-six thousand, six hundred forty".