266564657401 has 9 divisors (see below), whose sum is σ = 310089621999. Its totient is φ = 228480894264.

The previous prime is 266564657393. The next prime is 266564657417. The reversal of 266564657401 is 104756465662.

It is a happy number.

The square root of 266564657401 is 516299.

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

It can be written as a sum of positive squares in only one way, i.e., 47469515625 + 219095141776 = 217875^2 + 468076^2 .

It is not a de Polignac number, because 266564657401 - 2³ = 266564657393 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (266564657461) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 3577215 + ... + 3650971.

Almost surely, 2^266564657401 is an apocalyptic number.

266564657401 is the 516299-th square number.

266564657401 is the 258150-th centered octagonal number.

It is an amenable number.

266564657401 is a deficient number, since it is larger than the sum of its proper divisors (43524964598).

266564657401 is an frugal number, since it uses more digits than its factorization.

266564657401 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 147528 (or 73764 counting only the distinct ones).

The product of its (nonzero) digits is 7257600, while the sum is 52.

The spelling of 266564657401 in words is "two hundred sixty-six billion, five hundred sixty-four million, six hundred fifty-seven thousand, four hundred one".