66431040 has 112 divisors (see below), whose sum is σ = 227185728. Its totient is φ = 16349184.

The previous prime is 66431039. The next prime is 66431051. The reversal of 66431040 is 4013466.

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 66431040.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9819 + ... + 15141.

It is an arithmetic number, because the mean of its divisors is an integer number (2028444).

Almost surely, 2^66431040 is an apocalyptic number.

66431040 is a gapful number since it is divisible by the number (60) 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 66431040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (113592864).

66431040 is an abundant number, since it is smaller than the sum of its proper divisors (160754688).

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

66431040 is a wasteful number, since it uses less digits than its factorization.

66431040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5356 (or 5346 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 24.

The square root of 66431040 is about 8150.5239095410. The cubic root of 66431040 is about 405.0018594641.

The spelling of 66431040 in words is "sixty-six million, four hundred thirty-one thousand, forty".