66781400 has 48 divisors (see below), whose sum is σ = 177451440. Its totient is φ = 22896000.

The previous prime is 66781391. The next prime is 66781453. The reversal of 66781400 is 418766.

66781400 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 22451 + ... + 25250.

It is an arithmetic number, because the mean of its divisors is an integer number (3696905).

Almost surely, 2^66781400 is an apocalyptic number.

It is an amenable number.

66781400 is an abundant number, since it is smaller than the sum of its proper divisors (110670040).

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

66781400 is a wasteful number, since it uses less digits than its factorization.

66781400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 47724 (or 47715 counting only the distinct ones).

The product of its (nonzero) digits is 8064, while the sum is 32.

The square root of 66781400 is about 8171.9887420383. The cubic root of 66781400 is about 405.7126101611.

The spelling of 66781400 in words is "sixty-six million, seven hundred eighty-one thousand, four hundred".