1217535816672 has 768 divisors, whose sum is σ = 4301724672000. Its totient is φ = 334650839040.

The previous prime is 1217535816671. The next prime is 1217535816677. The reversal of 1217535816672 is 2766185357121.

1217535816672 is a `hidden beast` number, since 1 + 2 + 1 + 7 + 53 + 581 + 6 + 6 + 7 + 2 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1217535816671) by changing a digit.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 849640468 + ... + 849641900.

It is an arithmetic number, because the mean of its divisors is an integer number (5601204000).

Almost surely, 2^{1217535816672} is an apocalyptic number.

1217535816672 is a gapful number since it is divisible by the number (12) 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 1217535816672, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2150862336000).

1217535816672 is an abundant number, since it is smaller than the sum of its proper divisors (3084188855328).

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

1217535816672 is a wasteful number, since it uses less digits than its factorization.

1217535816672 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1581 (or 1553 counting only the distinct ones).

The product of its digits is 4233600, while the sum is 54.

The spelling of 1217535816672 in words is "one trillion, two hundred seventeen billion, five hundred thirty-five million, eight hundred sixteen thousand, six hundred seventy-two".