66031240 has 128 divisors (see below), whose sum is σ = 172523520. Its totient is φ = 22521600.

The previous prime is 66031223. The next prime is 66031241. The reversal of 66031240 is 4213066.

It is a Harshad number since it is a multiple of its sum of digits (22).

It is not an unprimeable number, because it can be changed into a prime (66031241) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 641029 + ... + 641131.

It is an arithmetic number, because the mean of its divisors is an integer number (1347840).

Almost surely, 2^66031240 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66031240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (86261760).

66031240 is an abundant number, since it is smaller than the sum of its proper divisors (106492280).

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

66031240 is a wasteful number, since it uses less digits than its factorization.

66031240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 203 (or 199 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 22.

The square root of 66031240 is about 8125.9608662607. The cubic root of 66031240 is about 404.1877537917.

The spelling of 66031240 in words is "sixty-six million, thirty-one thousand, two hundred forty".