266121780 has 48 divisors (see below), whose sum is σ = 751754304. Its totient is φ = 70336000.

The previous prime is 266121773. The next prime is 266121781. The reversal of 266121780 is 87121662.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (266121781) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12846 + ... + 26405.

It is an arithmetic number, because the mean of its divisors is an integer number (15661548).

Almost surely, 2^266121780 is an apocalyptic number.

266121780 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

266121780 is an abundant number, since it is smaller than the sum of its proper divisors (485632524).

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

266121780 is a wasteful number, since it uses less digits than its factorization.

266121780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39376 (or 39374 counting only the distinct ones).

The product of its (nonzero) digits is 8064, while the sum is 33.

The square root of 266121780 is about 16313.2394085295. The cubic root of 266121780 is about 643.2208888881.

The spelling of 266121780 in words is "two hundred sixty-six million, one hundred twenty-one thousand, seven hundred eighty".