1306812780 has 648 divisors, whose sum is σ = 5481901152. Its totient is φ = 245846016.

The previous prime is 1306812751. The next prime is 1306812811. The reversal of 1306812780 is 872186031.

1306812780 = 403² + 404² + ... + 1585².

1306812780 is a `hidden beast` number, since 1 + 306 + 81 + 278 + 0 = 666.

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

It is an unprimeable number.

It is a polite number, since it can be written in 215 ways as a sum of consecutive naturals, for example, 68779611 + ... + 68779629.

It is an arithmetic number, because the mean of its divisors is an integer number (8459724).

Almost surely, 2^1306812780 is an apocalyptic number.

1306812780 is a gapful number since it is divisible by the number (10) 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 1306812780, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2740950576).

1306812780 is an abundant number, since it is smaller than the sum of its proper divisors (4175088372).

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

1306812780 is a wasteful number, since it uses less digits than its factorization.

1306812780 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 103 (or 66 counting only the distinct ones).

The product of its (nonzero) digits is 16128, while the sum is 36.

The square root of 1306812780 is about 36149.8655599160. The cubic root of 1306812780 is about 1093.2960801389.

The spelling of 1306812780 in words is "one billion, three hundred six million, eight hundred twelve thousand, seven hundred eighty".