1291000656000 has 512 divisors, whose sum is σ = 4829775724800. Its totient is φ = 302174208000.

The previous prime is 1291000655999. The next prime is 1291000656047. The reversal of 1291000656000 is 6560001921.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 15269844 + ... + 15354156.

Almost surely, 2^{1291000656000} is an apocalyptic number.

1291000656000 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 1291000656000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2414887862400).

1291000656000 is an abundant number, since it is smaller than the sum of its proper divisors (3538775068800).

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

1291000656000 is a wasteful number, since it uses less digits than its factorization.

1291000656000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 84385 (or 84363 counting only the distinct ones).

The product of its (nonzero) digits is 3240, while the sum is 30.

Adding to 1291000656000 its reverse (6560001921), we get a palindrome (1297560657921).

The spelling of 1291000656000 in words is "one trillion, two hundred ninety-one billion, six hundred fifty-six thousand".