266664646 has 4 divisors (see below), whose sum is σ = 399996972. Its totient is φ = 133332322.

The previous prime is 266664637. The next prime is 266664647. The reversal of 266664646 is 646466662.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 646466662 = 2 ⋅323233331.

It is a super-2 number, since 2×266664646² = 142220066852610632, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 266664596 and 266664605.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (266664647) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 66666160 + ... + 66666163.

It is an arithmetic number, because the mean of its divisors is an integer number (99999243).

Almost surely, 2^266664646 is an apocalyptic number.

266664646 is a deficient number, since it is larger than the sum of its proper divisors (133332326).

266664646 is a wasteful number, since it uses less digits than its factorization.

266664646 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 133332325.

The product of its digits is 1492992, while the sum is 46.

The square root of 266664646 is about 16329.8697484089. The cubic root of 266664646 is about 643.6579639561.

The spelling of 266664646 in words is "two hundred sixty-six million, six hundred sixty-four thousand, six hundred forty-six".