66376991 has 8 divisors (see below), whose sum is σ = 68602464. Its totient is φ = 64180480.

The previous prime is 66376979. The next prime is 66376997. The reversal of 66376991 is 19967366.

It is a happy number.

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 66376991 - 2¹⁴ = 66360607 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66376997) 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, 2531 + ... + 11796.

It is an arithmetic number, because the mean of its divisors is an integer number (8575308).

Almost surely, 2^66376991 is an apocalyptic number.

66376991 is a deficient number, since it is larger than the sum of its proper divisors (2225473).

66376991 is a wasteful number, since it uses less digits than its factorization.

66376991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14481.

The product of its digits is 367416, while the sum is 47.

The square root of 66376991 is about 8147.2075584215. The cubic root of 66376991 is about 404.8919917235.

The spelling of 66376991 in words is "sixty-six million, three hundred seventy-six thousand, nine hundred ninety-one".