121783633920 has 768 divisors, whose sum is σ = 481682073600. Its totient is φ = 28983951360.

The previous prime is 121783633903. The next prime is 121783633943. The reversal of 121783633920 is 29336387121.

121783633920 is a `hidden beast` number, since 1 + 2 + 1 + 7 + 8 + 3 + 633 + 9 + 2 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (768).

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

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 111420894 + ... + 111421986.

It is an arithmetic number, because the mean of its divisors is an integer number (627190200).

Almost surely, 2^121783633920 is an apocalyptic number.

121783633920 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 121783633920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (240841036800).

121783633920 is an abundant number, since it is smaller than the sum of its proper divisors (359898439680).

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

121783633920 is a wasteful number, since it uses less digits than its factorization.

121783633920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1173 (or 1147 counting only the distinct ones).

The product of its (nonzero) digits is 326592, while the sum is 45.

The spelling of 121783633920 in words is "one hundred twenty-one billion, seven hundred eighty-three million, six hundred thirty-three thousand, nine hundred twenty".