66600091583 has 4 divisors (see below), whose sum is σ = 66603377808. Its totient is φ = 66596805360.

The previous prime is 66600091561. The next prime is 66600091603. The reversal of 66600091583 is 38519000666.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 38519000666 = 2 ⋅19259500333.

It is a cyclic number.

It is not a de Polignac number, because 66600091583 - 2¹² = 66600087487 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 (66600091483) 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, 1612523 + ... + 1653308.

It is an arithmetic number, because the mean of its divisors is an integer number (16650844452).

Almost surely, 2^66600091583 is an apocalyptic number.

66600091583 is a deficient number, since it is larger than the sum of its proper divisors (3286225).

66600091583 is a wasteful number, since it uses less digits than its factorization.

66600091583 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3286224.

The product of its (nonzero) digits is 233280, while the sum is 44.

The spelling of 66600091583 in words is "sixty-six billion, six hundred million, ninety-one thousand, five hundred eighty-three".