1217128203840 has 112 divisors (see below), whose sum is σ = 3866294682432. Its totient is φ = 324406880256.

The previous prime is 1217128203817. The next prime is 1217128203871. The reversal of 1217128203840 is 483028217121.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1633182 + ... + 2258658.

It is an arithmetic number, because the mean of its divisors is an integer number (34520488236).

Almost surely, 2^{1217128203840} is an apocalyptic number.

1217128203840 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 1217128203840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1933147341216).

1217128203840 is an abundant number, since it is smaller than the sum of its proper divisors (2649166478592).

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

1217128203840 is a wasteful number, since it uses less digits than its factorization.

1217128203840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 627524 (or 627514 counting only the distinct ones).

The product of its (nonzero) digits is 43008, while the sum is 39.

The spelling of 1217128203840 in words is "one trillion, two hundred seventeen billion, one hundred twenty-eight million, two hundred three thousand, eight hundred forty".