1281782216 has 64 divisors (see below), whose sum is σ = 2832278400. Its totient is φ = 536140800.

The previous prime is 1281782191. The next prime is 1281782219. The reversal of 1281782216 is 6122871821.

It is a self number, because there is not a number n which added to its sum of digits gives 1281782216.

It is not an unprimeable number, because it can be changed into a prime (1281782219) 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, 409136 + ... + 412256.

It is an arithmetic number, because the mean of its divisors is an integer number (44254350).

Almost surely, 2^1281782216 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1281782216, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1416139200).

1281782216 is an abundant number, since it is smaller than the sum of its proper divisors (1550496184).

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

1281782216 is a wasteful number, since it uses less digits than its factorization.

1281782216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3510 (or 3506 counting only the distinct ones).

The product of its digits is 21504, while the sum is 38.

The square root of 1281782216 is about 35801.9862018855. The cubic root of 1281782216 is about 1086.2707377822.

The spelling of 1281782216 in words is "one billion, two hundred eighty-one million, seven hundred eighty-two thousand, two hundred sixteen".