121657921781760 has 2880 divisors, whose sum is σ = 549234896716800. Its totient is φ = 25320379908096.

The previous prime is 121657921781743. The next prime is 121657921781849. The reversal of 121657921781760 is 67187129756121.

121657921781760 is a `hidden beast` number, since 1 + 21 + 6 + 579 + 21 + 7 + 8 + 17 + 6 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (2880).

It is a super-3 number, since 3×121657921781760³ (a number of 43 digits) contains 333 as substring.

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 191 ways as a sum of consecutive naturals, for example, 111306423774 + ... + 111306424866.

It is an arithmetic number, because the mean of its divisors is an integer number (190706561360).

Almost surely, 2^{121657921781760} is an apocalyptic number.

121657921781760 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 121657921781760, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (274617448358400).

121657921781760 is an abundant number, since it is smaller than the sum of its proper divisors (427576974935040).

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

121657921781760 is a wasteful number, since it uses less digits than its factorization.

121657921781760 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1241 (or 1202 counting only the distinct ones).

The product of its (nonzero) digits is 17781120, while the sum is 63.

The spelling of 121657921781760 in words is "one hundred twenty-one trillion, six hundred fifty-seven billion, nine hundred twenty-one million, seven hundred eighty-one thousand, seven hundred sixty".