66140691 has 8 divisors (see below), whose sum is σ = 92829120. Its totient is φ = 41773032.

The previous prime is 66140687. The next prime is 66140707. The reversal of 66140691 is 19604166.

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

It is not a de Polignac number, because 66140691 - 2² = 66140687 is a prime.

It is a Smith number, since the sum of its digits (33) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (66140611) 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, 580125 + ... + 580238.

It is an arithmetic number, because the mean of its divisors is an integer number (11603640).

Almost surely, 2^66140691 is an apocalyptic number.

66140691 is a deficient number, since it is larger than the sum of its proper divisors (26688429).

66140691 is a wasteful number, since it uses less digits than its factorization.

66140691 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1160385.

The product of its (nonzero) digits is 7776, while the sum is 33.

The square root of 66140691 is about 8132.6927275042. The cubic root of 66140691 is about 404.4109528586.

The spelling of 66140691 in words is "sixty-six million, one hundred forty thousand, six hundred ninety-one".