1217220638688 has 72 divisors (see below), whose sum is σ = 3580832291400. Its totient is φ = 391749168384.

The previous prime is 1217220638687. The next prime is 1217220638779. The reversal of 1217220638688 is 8868360227121.

1217220638688 is a `hidden beast` number, since 12 + 172 + 2 + 0 + 6 + 386 + 88 = 666.

It is a tau number, because it is divible by the number of its divisors (72).

It is a super-2 number, since 2×1217220638688² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1217220638687) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 72861658 + ... + 72878361.

It is an arithmetic number, because the mean of its divisors is an integer number (49733781825).

Almost surely, 2^{1217220638688} is an apocalyptic number.

1217220638688 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

1217220638688 is an abundant number, since it is smaller than the sum of its proper divisors (2363611652712).

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

1217220638688 is a wasteful number, since it uses less digits than its factorization.

1217220638688 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 145740064 (or 145740053 counting only the distinct ones).

The product of its (nonzero) digits is 3096576, while the sum is 54.

The spelling of 1217220638688 in words is "one trillion, two hundred seventeen billion, two hundred twenty million, six hundred thirty-eight thousand, six hundred eighty-eight".