66781140 has 24 divisors (see below), whose sum is σ = 186987360. Its totient is φ = 17808288.

The previous prime is 66781123. The next prime is 66781147. The reversal of 66781140 is 4118766.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66781147) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 556450 + ... + 556569.

It is an arithmetic number, because the mean of its divisors is an integer number (7791140).

Almost surely, 2^66781140 is an apocalyptic number.

66781140 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

66781140 is an abundant number, since it is smaller than the sum of its proper divisors (120206220).

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

66781140 is a wasteful number, since it uses less digits than its factorization.

66781140 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1113031 (or 1113029 counting only the distinct ones).

The product of its (nonzero) digits is 8064, while the sum is 33.

The square root of 66781140 is about 8171.9728340224. The cubic root of 66781140 is about 405.7120836402.

The spelling of 66781140 in words is "sixty-six million, seven hundred eighty-one thousand, one hundred forty".