121936405920 has 432 divisors, whose sum is σ = 474665274720. Its totient is φ = 26230235136.

The previous prime is 121936405897. The next prime is 121936405939. The reversal of 121936405920 is 29504639121.

It is a super-2 number, since 2×121936405920² (a number of 23 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 6788311 + ... + 6806249.

It is an arithmetic number, because the mean of its divisors is an integer number (1098762210).

Almost surely, 2^121936405920 is an apocalyptic number.

121936405920 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 121936405920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (237332637360).

121936405920 is an abundant number, since it is smaller than the sum of its proper divisors (352728868800).

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

121936405920 is a wasteful number, since it uses less digits than its factorization.

121936405920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18005 (or 17973 counting only the distinct ones).

The product of its (nonzero) digits is 116640, while the sum is 42.

The spelling of 121936405920 in words is "one hundred twenty-one billion, nine hundred thirty-six million, four hundred five thousand, nine hundred twenty".