66362396881 has 15 divisors (see below), whose sum is σ = 73032486955. Its totient is φ = 60301114720.

The previous prime is 66362396857. The next prime is 66362396909. The reversal of 66362396881 is 18869326366.

It is a happy number.

The square root of 66362396881 is 257609.

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

66362396881 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 16793827281 + 49568569600 = 129591^2 + 222640^2 .

It is a de Polignac number, because none of the positive numbers 2^k-66362396881 is a prime.

It is a super-2 number, since 2×66362396881² (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 (66362396081) by changing a digit.

It is a polite number, since it can be written in 14 ways as a sum of consecutive naturals, for example, 31169625 + ... + 31171753.

Almost surely, 2^66362396881 is an apocalyptic number.

66362396881 is the 257609-th square number.

66362396881 is the 128805-th centered octagonal number.

It is an amenable number.

66362396881 is a deficient number, since it is larger than the sum of its proper divisors (6670090074).

66362396881 is an frugal number, since it uses more digits than its factorization.

66362396881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4302 (or 2140 counting only the distinct ones).

The product of its digits is 13436928, while the sum is 58.

The spelling of 66362396881 in words is "sixty-six billion, three hundred sixty-two million, three hundred ninety-six thousand, eight hundred eighty-one".