121999445568 has 896 divisors, whose sum is σ = 485190881280. Its totient is φ = 29030400000.

The previous prime is 121999445551. The next prime is 121999445573. The reversal of 121999445568 is 865544999121.

121999445568 is a `hidden beast` number, since 1 + 2 + 1 + 99 + 94 + 455 + 6 + 8 = 666.

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

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 434161588 + ... + 434161868.

It is an arithmetic number, because the mean of its divisors is an integer number (541507680).

Almost surely, 2^121999445568 is an apocalyptic number.

121999445568 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 121999445568, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (242595440640).

121999445568 is an abundant number, since it is smaller than the sum of its proper divisors (363191435712).

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

121999445568 is a wasteful number, since it uses less digits than its factorization.

121999445568 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 584 (or 568 counting only the distinct ones).

The product of its digits is 27993600, while the sum is 63.

The spelling of 121999445568 in words is "one hundred twenty-one billion, nine hundred ninety-nine million, four hundred forty-five thousand, five hundred sixty-eight".