66993858 has 32 divisors (see below), whose sum is σ = 150206400. Its totient is φ = 22131648.

The previous prime is 66993853. The next prime is 66993859. The reversal of 66993858 is 85839966.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is not an unprimeable number, because it can be changed into a prime (66993853) 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 15 ways as a sum of consecutive naturals, for example, 613 + ... + 11591.

It is an arithmetic number, because the mean of its divisors is an integer number (4693950).

Almost surely, 2^66993858 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66993858, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (75103200).

66993858 is an abundant number, since it is smaller than the sum of its proper divisors (83212542).

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

66993858 is a wasteful number, since it uses less digits than its factorization.

66993858 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11103 (or 11097 counting only the distinct ones).

The product of its digits is 2799360, while the sum is 54.

The square root of 66993858 is about 8184.9775809100. The cubic root of 66993858 is about 406.1423987059.

The spelling of 66993858 in words is "sixty-six million, nine hundred ninety-three thousand, eight hundred fifty-eight".