66817127580506 has 4 divisors (see below), whose sum is σ = 100225691370762. Its totient is φ = 33408563790252.

The previous prime is 66817127580503. The next prime is 66817127580559. The reversal of 66817127580506 is 60508572171866.

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

It can be written as a sum of positive squares in only one way, i.e., 37518626310025 + 29298501270481 = 6125245^2 + 5412809^2 .

It is a super-2 number, since 2×66817127580506² (a number of 28 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (66817127580503) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 16704281895125 + ... + 16704281895128.

Almost surely, 2^{66817127580506} is an apocalyptic number.

66817127580506 is a deficient number, since it is larger than the sum of its proper divisors (33408563790256).

66817127580506 is a wasteful number, since it uses less digits than its factorization.

66817127580506 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33408563790255.

The product of its (nonzero) digits is 33868800, while the sum is 62.

The spelling of 66817127580506 in words is "sixty-six trillion, eight hundred seventeen billion, one hundred twenty-seven million, five hundred eighty thousand, five hundred six".