1221693677568 has 2016 divisors, whose sum is σ = 4921662902400. Its totient is φ = 297568567296.

The previous prime is 1221693677513. The next prime is 1221693677587. The reversal of 1221693677568 is 8657763961221.

1221693677568 is a `hidden beast` number, since 1 + 2 + 2 + 1 + 6 + 9 + 3 + 67 + 7 + 568 = 666.

It is a tau number, because it is divible by the number of its divisors (2016).

It is a super-3 number, since 3×1221693677568³ (a number of 37 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 42127368178 + ... + 42127368206.

Almost surely, 2^{1221693677568} is an apocalyptic number.

1221693677568 is a gapful number since it is divisible by the number (18) 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 1221693677568, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2460831451200).

1221693677568 is an abundant number, since it is smaller than the sum of its proper divisors (3699969224832).

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

1221693677568 is a wasteful number, since it uses less digits than its factorization.

1221693677568 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 127 (or 77 counting only the distinct ones).

The product of its digits is 45722880, while the sum is 63.

The spelling of 1221693677568 in words is "one trillion, two hundred twenty-one billion, six hundred ninety-three million, six hundred seventy-seven thousand, five hundred sixty-eight".