66663240 has 128 divisors (see below), whose sum is σ = 232485120. Its totient is φ = 14976000.

The previous prime is 66663217. The next prime is 66663271. The reversal of 66663240 is 4236666.

It is a Smith number, since the sum of its digits (33) coincides with the sum of the digits of its prime factors.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 50590 + ... + 51890.

It is an arithmetic number, because the mean of its divisors is an integer number (1816290).

Almost surely, 2^66663240 is an apocalyptic number.

66663240 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 66663240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (116242560).

66663240 is an abundant number, since it is smaller than the sum of its proper divisors (165821880).

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

66663240 is a wasteful number, since it uses less digits than its factorization.

66663240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1383 (or 1379 counting only the distinct ones).

The product of its (nonzero) digits is 31104, while the sum is 33.

The square root of 66663240 is about 8164.7559669595. The cubic root of 66663240 is about 405.4731856929.

The spelling of 66663240 in words is "sixty-six million, six hundred sixty-three thousand, two hundred forty".