120991608640 has 112 divisors (see below), whose sum is σ = 329548004352. Its totient is φ = 41447817216.

The previous prime is 120991608611. The next prime is 120991608643. The reversal of 120991608640 is 46806199021.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (112).

It is a super-2 number, since 2×120991608640² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (120991608643) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2703889 + ... + 2748271.

It is an arithmetic number, because the mean of its divisors is an integer number (2942392896).

Almost surely, 2^120991608640 is an apocalyptic number.

120991608640 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 120991608640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (164774002176).

120991608640 is an abundant number, since it is smaller than the sum of its proper divisors (208556395712).

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

120991608640 is a wasteful number, since it uses less digits than its factorization.

120991608640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45624 (or 45614 counting only the distinct ones).

The product of its (nonzero) digits is 186624, while the sum is 46.

The spelling of 120991608640 in words is "one hundred twenty billion, nine hundred ninety-one million, six hundred eight thousand, six hundred forty".