121910791680 has 480 divisors, whose sum is σ = 448697620800. Its totient is φ = 30484463616.

The previous prime is 121910791633. The next prime is 121910791699. The reversal of 121910791680 is 86197019121.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (480).

It is a super-2 number, since 2×121910791680² (a number of 23 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 171947166 + ... + 171947874.

It is an arithmetic number, because the mean of its divisors is an integer number (934786710).

Almost surely, 2^121910791680 is an apocalyptic number.

121910791680 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 121910791680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (224348810400).

121910791680 is an abundant number, since it is smaller than the sum of its proper divisors (326786829120).

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

121910791680 is a wasteful number, since it uses less digits than its factorization.

121910791680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1194 (or 1175 counting only the distinct ones).

The product of its (nonzero) digits is 54432, while the sum is 45.

The spelling of 121910791680 in words is "one hundred twenty-one billion, nine hundred ten million, seven hundred ninety-one thousand, six hundred eighty".