1266543216 has 240 divisors, whose sum is σ = 3899750400. Its totient is φ = 397281024.

The previous prime is 1266543181. The next prime is 1266543221. The reversal of 1266543216 is 6123456621.

It is a Harshad number since it is a multiple of its sum of digits (36).

Its product of digits (51840) is a multiple of the sum of its prime divisors (320).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 5299225 + ... + 5299463.

It is an arithmetic number, because the mean of its divisors is an integer number (16248960).

Almost surely, 2^1266543216 is an apocalyptic number.

1266543216 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1266543216, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1949875200).

1266543216 is an abundant number, since it is smaller than the sum of its proper divisors (2633207184).

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

1266543216 is a wasteful number, since it uses less digits than its factorization.

1266543216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 338 (or 320 counting only the distinct ones).

The product of its digits is 51840, while the sum is 36.

The square root of 1266543216 is about 35588.5264657024. The cubic root of 1266543216 is about 1081.9487039527.

Adding to 1266543216 its reverse (6123456621), we get a palindrome (7389999837).

The spelling of 1266543216 in words is "one billion, two hundred sixty-six million, five hundred forty-three thousand, two hundred sixteen".