1281116533620 has 288 divisors, whose sum is σ = 4791710891520. Its totient is φ = 252195068160.

The previous prime is 1281116533603. The next prime is 1281116533621. The reversal of 1281116533620 is 263356111821.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1281116533621) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 428014 + ... + 1656933.

It is an arithmetic number, because the mean of its divisors is an integer number (16637885040).

Almost surely, 2^{1281116533620} is an apocalyptic number.

1281116533620 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 1281116533620, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2395855445760).

1281116533620 is an abundant number, since it is smaller than the sum of its proper divisors (3510594357900).

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

1281116533620 is a wasteful number, since it uses less digits than its factorization.

1281116533620 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2085003 (or 2084994 counting only the distinct ones).

The product of its (nonzero) digits is 51840, while the sum is 39.

The spelling of 1281116533620 in words is "one trillion, two hundred eighty-one billion, one hundred sixteen million, five hundred thirty-three thousand, six hundred twenty".