121380785820 has 480 divisors, whose sum is σ = 450767708160. Its totient is φ = 26756282880.

The previous prime is 121380785761. The next prime is 121380785821. The reversal of 121380785820 is 28587083121.

121380785820 is a `hidden beast` number, since 121 + 380 + 78 + 5 + 82 + 0 = 666.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121380785821) by changing a digit.

It is a polite number, since it can be written in 159 ways as a sum of consecutive naturals, for example, 171199626 + ... + 171200334.

It is an arithmetic number, because the mean of its divisors is an integer number (939099392).

Almost surely, 2^121380785820 is an apocalyptic number.

121380785820 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 121380785820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (225383854080).

121380785820 is an abundant number, since it is smaller than the sum of its proper divisors (329386922340).

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

121380785820 is a wasteful number, since it uses less digits than its factorization.

121380785820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1255 (or 1244 counting only the distinct ones).

The product of its (nonzero) digits is 215040, while the sum is 45.

The spelling of 121380785820 in words is "one hundred twenty-one billion, three hundred eighty million, seven hundred eighty-five thousand, eight hundred twenty".