1280849521536 has 640 divisors, whose sum is σ = 4302504138240. Its totient is φ = 375300034560.

The previous prime is 1280849521493. The next prime is 1280849521573. The reversal of 1280849521536 is 6351259480821.

1280849521536 is a `hidden beast` number, since 1 + 2 + 8 + 0 + 84 + 9 + 5 + 21 + 536 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 815307631 + ... + 815309201.

It is an arithmetic number, because the mean of its divisors is an integer number (6722662716).

Almost surely, 2^{1280849521536} is an apocalyptic number.

1280849521536 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 1280849521536, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2151252069120).

1280849521536 is an abundant number, since it is smaller than the sum of its proper divisors (3021654616704).

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

1280849521536 is a wasteful number, since it uses less digits than its factorization.

1280849521536 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1896 (or 1875 counting only the distinct ones).

The product of its (nonzero) digits is 4147200, while the sum is 54.

The spelling of 1280849521536 in words is "one trillion, two hundred eighty billion, eight hundred forty-nine million, five hundred twenty-one thousand, five hundred thirty-six".