66772110409 has 3 divisors (see below), whose sum is σ = 66772368813. Its totient is φ = 66771852006.

The previous prime is 66772110401. The next prime is 66772110413. The reversal of 66772110409 is 90401127766.

The square root of 66772110409 is 258403.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is not a de Polignac number, because 66772110409 - 2³ = 66772110401 is a prime.

It is a super-2 number, since 2×66772110409² (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 (66772110401) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 129202 + ... + 387604.

It is an arithmetic number, because the mean of its divisors is an integer number (22257456271).

Almost surely, 2^66772110409 is an apocalyptic number.

66772110409 is the 258403-rd square number.

66772110409 is the 129202-nd centered octagonal number.

It is an amenable number.

66772110409 is a deficient number, since it is larger than the sum of its proper divisors (258404).

66772110409 is an frugal number, since it uses more digits than its factorization.

66772110409 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 516806 (or 258403 counting only the distinct ones).

The product of its (nonzero) digits is 127008, while the sum is 43.

The spelling of 66772110409 in words is "sixty-six billion, seven hundred seventy-two million, one hundred ten thousand, four hundred nine".