1281909747456 has 648 divisors, whose sum is σ = 4140761526720. Its totient is φ = 379085930496.

The previous prime is 1281909747439. The next prime is 1281909747487. The reversal of 1281909747456 is 6547479091821.

1281909747456 is a `hidden beast` number, since 1 + 2 + 8 + 1 + 90 + 97 + 4 + 7 + 456 = 666.

It is a junction number, because it is equal to n+sod(n) for n = 1281909747393 and 1281909747402.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 4375118446 + ... + 4375118738.

Almost surely, 2^{1281909747456} is an apocalyptic number.

1281909747456 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 1281909747456, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2070380763360).

1281909747456 is an abundant number, since it is smaller than the sum of its proper divisors (2858851779264).

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

1281909747456 is a wasteful number, since it uses less digits than its factorization.

1281909747456 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 493 (or 433 counting only the distinct ones).

The product of its (nonzero) digits is 30481920, while the sum is 63.

The spelling of 1281909747456 in words is "one trillion, two hundred eighty-one billion, nine hundred nine million, seven hundred forty-seven thousand, four hundred fifty-six".