266821564 has 12 divisors (see below), whose sum is σ = 474592888. Its totient is φ = 131223600.

The previous prime is 266821561. The next prime is 266821567. The reversal of 266821564 is 465128662.

It is an interprime number because it is at equal distance from previous prime (266821561) and next prime (266821567).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (266821561) 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, 546522 + ... + 547009.

Almost surely, 2^266821564 is an apocalyptic number.

It is an amenable number.

266821564 is a deficient number, since it is larger than the sum of its proper divisors (207771324).

266821564 is a wasteful number, since it uses less digits than its factorization.

266821564 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1093596 (or 1093594 counting only the distinct ones).

The product of its digits is 138240, while the sum is 40.

The square root of 266821564 is about 16334.6736728959. The cubic root of 266821564 is about 643.7841920570.

The spelling of 266821564 in words is "two hundred sixty-six million, eight hundred twenty-one thousand, five hundred sixty-four".