66375381 has 8 divisors (see below), whose sum is σ = 89951584. Its totient is φ = 43524720.

The previous prime is 66375367. The next prime is 66375389. The reversal of 66375381 is 18357366.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a de Polignac number, because none of the positive numbers 2^k-66375381 is a prime.

It is a super-2 number, since 2×66375381² = 8811382405790322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66375389) 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 7 ways as a sum of consecutive naturals, for example, 181171 + ... + 181536.

It is an arithmetic number, because the mean of its divisors is an integer number (11243948).

Almost surely, 2^66375381 is an apocalyptic number.

66375381 is a gapful number since it is divisible by the number (61) formed by its first and last digit.

It is an amenable number.

66375381 is a deficient number, since it is larger than the sum of its proper divisors (23576203).

66375381 is a wasteful number, since it uses less digits than its factorization.

66375381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 362771.

The product of its digits is 90720, while the sum is 39.

The square root of 66375381 is about 8147.1087509619. The cubic root of 66375381 is about 404.8887180922. Note that the first 3 decimals are identical.

The spelling of 66375381 in words is "sixty-six million, three hundred seventy-five thousand, three hundred eighty-one".