121358725920 has 144 divisors (see below), whose sum is σ = 415677520440. Its totient is φ = 32241917952.

The previous prime is 121358725861. The next prime is 121358725927. The reversal of 121358725920 is 29527853121.

121358725920 is a `hidden beast` number, since 1 + 2 + 1 + 3 + 58 + 7 + 2 + 592 + 0 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 34137735696 + 87220990224 = 184764^2 + 295332^2 .

It is a tau number, because it is divible by the number of its divisors (144).

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

It is not an unprimeable number, because it can be changed into a prime (121358725927) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 230712 + ... + 544008.

Almost surely, 2^121358725920 is an apocalyptic number.

121358725920 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 121358725920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (207838760220).

121358725920 is an abundant number, since it is smaller than the sum of its proper divisors (294318794520).

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

121358725920 is a wasteful number, since it uses less digits than its factorization.

121358725920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 313587 (or 313576 counting only the distinct ones).

The product of its (nonzero) digits is 302400, while the sum is 45.

The spelling of 121358725920 in words is "one hundred twenty-one billion, three hundred fifty-eight million, seven hundred twenty-five thousand, nine hundred twenty".