66968928 has 144 divisors (see below), whose sum is σ = 212075136. Its totient is φ = 19906560.

The previous prime is 66968861. The next prime is 66968929. The reversal of 66968928 is 82986966.

It is a tau number, because it is divible by the number of its divisors (144).

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66968929) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 115776 + ... + 116352.

It is an arithmetic number, because the mean of its divisors is an integer number (1472744).

Almost surely, 2^66968928 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 66968928, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (106037568).

66968928 is an abundant number, since it is smaller than the sum of its proper divisors (145106208).

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

66968928 is a wasteful number, since it uses less digits than its factorization.

66968928 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 637 (or 626 counting only the distinct ones).

The product of its digits is 2239488, while the sum is 54.

The square root of 66968928 is about 8183.4545272764. The cubic root of 66968928 is about 406.0920140562.

It can be divided in two parts, 66968 and 928, that added together give a triangular number (67896 = T₃₆₈).

The spelling of 66968928 in words is "sixty-six million, nine hundred sixty-eight thousand, nine hundred twenty-eight".