66800631893 has 4 divisors (see below), whose sum is σ = 68061021228. Its totient is φ = 65540242560.

The previous prime is 66800631847. The next prime is 66800631983. The reversal of 66800631893 is 39813600866.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 37169140849 + 29631491044 = 192793^2 + 172138^2 .

It is a cyclic number.

It is not a de Polignac number, because 66800631893 - 2¹² = 66800627797 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 (66800631803) 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, 630194588 + ... + 630194693.

It is an arithmetic number, because the mean of its divisors is an integer number (17015255307).

Almost surely, 2^66800631893 is an apocalyptic number.

It is an amenable number.

66800631893 is a deficient number, since it is larger than the sum of its proper divisors (1260389335).

66800631893 is a wasteful number, since it uses less digits than its factorization.

66800631893 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1260389334.

The product of its (nonzero) digits is 1119744, while the sum is 50.

The spelling of 66800631893 in words is "sixty-six billion, eight hundred million, six hundred thirty-one thousand, eight hundred ninety-three".