66188774399 has 16 divisors (see below), whose sum is σ = 74887956000. Its totient is φ = 57947272320.

The previous prime is 66188774383. The next prime is 66188774401. The reversal of 66188774399 is 99347788166.

It is a cyclic number.

It is not a de Polignac number, because 66188774399 - 2⁴ = 66188774383 is a prime.

It is a super-2 number, since 2×66188774399² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66188770399) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 142604 + ... + 390785.

It is an arithmetic number, because the mean of its divisors is an integer number (4680497250).

Almost surely, 2^66188774399 is an apocalyptic number.

66188774399 is a deficient number, since it is larger than the sum of its proper divisors (8699181601).

66188774399 is a wasteful number, since it uses less digits than its factorization.

66188774399 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 533818.

The product of its digits is 109734912, while the sum is 68.

The spelling of 66188774399 in words is "sixty-six billion, one hundred eighty-eight million, seven hundred seventy-four thousand, three hundred ninety-nine".