66693381 has 16 divisors (see below), whose sum is σ = 90059904. Its totient is φ = 43898624.

The previous prime is 66693377. The next prime is 66693409. The reversal of 66693381 is 18339666.

It is a cyclic number.

It is not a de Polignac number, because 66693381 - 2² = 66693377 is a prime.

It is a super-2 number, since 2×66693381² = 8896014138422322, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66693581) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 107785 + ... + 108401.

It is an arithmetic number, because the mean of its divisors is an integer number (5628744).

Almost surely, 2^66693381 is an apocalyptic number.

It is an amenable number.

66693381 is a deficient number, since it is larger than the sum of its proper divisors (23366523).

66693381 is a wasteful number, since it uses less digits than its factorization.

66693381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1020.

The product of its digits is 139968, while the sum is 42.

The square root of 66693381 is about 8166.6015575636. The cubic root of 66693381 is about 405.5342864627.

The spelling of 66693381 in words is "sixty-six million, six hundred ninety-three thousand, three hundred eighty-one".