266066638 has 4 divisors (see below), whose sum is σ = 399099960. Its totient is φ = 133033318.

The previous prime is 266066597. The next prime is 266066639. The reversal of 266066638 is 836660662.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 836660662 = 2 ⋅418330331.

It is a junction number, because it is equal to n+sod(n) for n = 266066594 and 266066603.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (266066639) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 66516658 + ... + 66516661.

It is an arithmetic number, because the mean of its divisors is an integer number (99774990).

Almost surely, 2^266066638 is an apocalyptic number.

266066638 is a deficient number, since it is larger than the sum of its proper divisors (133033322).

266066638 is a wasteful number, since it uses less digits than its factorization.

266066638 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 133033321.

The product of its (nonzero) digits is 373248, while the sum is 43.

The square root of 266066638 is about 16311.5492213339. The cubic root of 266066638 is about 643.1764594339.

The spelling of 266066638 in words is "two hundred sixty-six million, sixty-six thousand, six hundred thirty-eight".