66381989 has 8 divisors (see below), whose sum is σ = 67459392. Its totient is φ = 65311360.

The previous prime is 66381967. The next prime is 66382007. The reversal of 66381989 is 98918366.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66381989 is a prime.

It is a super-2 number, since 2×66381989² = 8813136927192242, 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 (66381919) 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, 20309 + ... + 23349.

It is an arithmetic number, because the mean of its divisors is an integer number (8432424).

Almost surely, 2^66381989 is an apocalyptic number.

It is an amenable number.

66381989 is a deficient number, since it is larger than the sum of its proper divisors (1077403).

66381989 is a wasteful number, since it uses less digits than its factorization.

66381989 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3387.

The product of its digits is 559872, while the sum is 50.

The square root of 66381989 is about 8147.5142835100. The cubic root of 66381989 is about 404.9021538763.

The spelling of 66381989 in words is "sixty-six million, three hundred eighty-one thousand, nine hundred eighty-nine".