667569068401 has 3 divisors (see below), whose sum is σ = 667569885451. Its totient is φ = 667568251352.

The previous prime is 667569068399. The next prime is 667569068443. The reversal of 667569068401 is 104860965766.

The square root of 667569068401 is 817049.

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 can be written as a sum of positive squares in only one way, i.e., 605049066801 + 62520001600 = 777849^2 + 250040^2 .

It is not a de Polignac number, because 667569068401 - 2¹ = 667569068399 is a prime.

It is a super-2 number, since 2×667569068401² (a number of 24 digits) contains 22 as substring.

It is a Smith number, since the sum of its digits (58) coincides with the sum of the digits of its prime factors.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (667569068471) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 408525 + ... + 1225573.

Almost surely, 2^667569068401 is an apocalyptic number.

667569068401 is the 817049-th square number.

667569068401 is the 408525-th centered octagonal number.

It is an amenable number.

667569068401 is a deficient number, since it is larger than the sum of its proper divisors (817050).

667569068401 is an frugal number, since it uses more digits than its factorization.

667569068401 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1634098 (or 817049 counting only the distinct ones).

The product of its (nonzero) digits is 13063680, while the sum is 58.

The spelling of 667569068401 in words is "six hundred sixty-seven billion, five hundred sixty-nine million, sixty-eight thousand, four hundred one".