121777920 has 324 divisors, whose sum is σ = 474947928. Its totient is φ = 28569600.

The previous prime is 121777871. The next prime is 121777933. The reversal of 121777920 is 29777121.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 3928305 + ... + 3928335.

Almost surely, 2^121777920 is an apocalyptic number.

121777920 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 121777920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (237473964).

121777920 is an abundant number, since it is smaller than the sum of its proper divisors (353170008).

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

121777920 is a wasteful number, since it uses less digits than its factorization.

121777920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 100 (or 52 counting only the distinct ones).

The product of its (nonzero) digits is 12348, while the sum is 36.

The square root of 121777920 is about 11035.3033487983. The cubic root of 121777920 is about 495.6664424011. Note that the first 3 decimals are identical.

The spelling of 121777920 in words is "one hundred twenty-one million, seven hundred seventy-seven thousand, nine hundred twenty".