266638398 has 24 divisors (see below), whose sum is σ = 577455768. Its totient is φ = 82042272.

The previous prime is 266638397. The next prime is 266638423. The reversal of 266638398 is 893836662.

It is a self number, because there is not a number n which added to its sum of digits gives 266638398.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (266638397) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 130465 + ... + 132492.

It is an arithmetic number, because the mean of its divisors is an integer number (24060657).

Almost surely, 2^266638398 is an apocalyptic number.

266638398 is an abundant number, since it is smaller than the sum of its proper divisors (310817370).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

266638398 is a wasteful number, since it uses less digits than its factorization.

266638398 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 262988 (or 262975 counting only the distinct ones).

The product of its digits is 2239488, while the sum is 51.

The square root of 266638398 is about 16329.0660480016. The cubic root of 266638398 is about 643.6368446854.

The spelling of 266638398 in words is "two hundred sixty-six million, six hundred thirty-eight thousand, three hundred ninety-eight".