66390826129 has 4 divisors (see below), whose sum is σ = 66489475876. Its totient is φ = 66292176384.

The previous prime is 66390826123. The next prime is 66390826193. The reversal of 66390826129 is 92162809366.

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 8925147729 + 57465678400 = 94473^2 + 239720^2 .

It is a cyclic number.

It is not a de Polignac number, because 66390826129 - 2⁷ = 66390826001 is a prime.

It is a super-2 number, since 2×66390826129² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66390826123) 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, 49323864 + ... + 49325209.

It is an arithmetic number, because the mean of its divisors is an integer number (16622368969).

Almost surely, 2^66390826129 is an apocalyptic number.

It is an amenable number.

66390826129 is a deficient number, since it is larger than the sum of its proper divisors (98649747).

66390826129 is an equidigital number, since it uses as much as digits as its factorization.

66390826129 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 98649746.

The product of its (nonzero) digits is 1679616, while the sum is 52.

The spelling of 66390826129 in words is "sixty-six billion, three hundred ninety million, eight hundred twenty-six thousand, one hundred twenty-nine".