66991602 has 8 divisors (see below), whose sum is σ = 133983216. Its totient is φ = 22330532.

The previous prime is 66991601. The next prime is 66991607. The reversal of 66991602 is 20619966.

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

66991602 is an admirable number.

It is not an unprimeable number, because it can be changed into a prime (66991601) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5582628 + ... + 5582639.

It is an arithmetic number, because the mean of its divisors is an integer number (16747902).

Almost surely, 2^66991602 is an apocalyptic number.

66991602 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

66991602 is a wasteful number, since it uses less digits than its factorization.

66991602 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11165272.

The product of its (nonzero) digits is 34992, while the sum is 39.

The square root of 66991602 is about 8184.8397662996. The cubic root of 66991602 is about 406.1378397430.

The spelling of 66991602 in words is "sixty-six million, nine hundred ninety-one thousand, six hundred two".