66680381 has 8 divisors (see below), whose sum is σ = 70721664. Its totient is φ = 62734320.

The previous prime is 66680377. The next prime is 66680387. The reversal of 66680381 is 18308666.

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

It is a cyclic number.

It is not a de Polignac number, because 66680381 - 2² = 66680377 is a prime.

It is a super-2 number, since 2×66680381² = 8892546420610322, 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 (66680387) 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, 22361 + ... + 25166.

It is an arithmetic number, because the mean of its divisors is an integer number (8840208).

Almost surely, 2^66680381 is an apocalyptic number.

66680381 is a gapful number since it is divisible by the number (61) formed by its first and last digit.

It is an amenable number.

66680381 is a deficient number, since it is larger than the sum of its proper divisors (4041283).

66680381 is a wasteful number, since it uses less digits than its factorization.

66680381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47611.

The product of its (nonzero) digits is 41472, while the sum is 38.

The square root of 66680381 is about 8165.8055940611. The cubic root of 66680381 is about 405.5079355804.

The spelling of 66680381 in words is "sixty-six million, six hundred eighty thousand, three hundred eighty-one".