120651721506 has 96 divisors (see below), whose sum is σ = 290527106688. Its totient is φ = 37428842880.

The previous prime is 120651721501. The next prime is 120651721507. The reversal of 120651721506 is 605127156021.

120651721506 is a `hidden beast` number, since 1 + 20 + 65 + 1 + 72 + 1 + 506 = 666.

It is a super-2 number, since 2×120651721506² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (120651721501) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 267726 + ... + 559446.

It is an arithmetic number, because the mean of its divisors is an integer number (3026324028).

Almost surely, 2^120651721506 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 120651721506, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (145263553344).

120651721506 is an abundant number, since it is smaller than the sum of its proper divisors (169875385182).

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

120651721506 is a wasteful number, since it uses less digits than its factorization.

120651721506 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 291798 (or 291786 counting only the distinct ones).

The product of its (nonzero) digits is 25200, while the sum is 36.

Adding to 120651721506 its reverse (605127156021), we get a palindrome (725778877527).

The spelling of 120651721506 in words is "one hundred twenty billion, six hundred fifty-one million, seven hundred twenty-one thousand, five hundred six".