991384138332 has 288 divisors, whose sum is σ = 2935296000000. Its totient is φ = 276308952192.

The previous prime is 991384138319. The next prime is 991384138453. The reversal of 991384138332 is 233831483199.

991384138332 is a `hidden beast` number, since 9 + 91 + 38 + 413 + 83 + 32 = 666.

It is a super-2 number, since 2×991384138332² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 661362919 + ... + 661364417.

It is an arithmetic number, because the mean of its divisors is an integer number (10192000000).

Almost surely, 2^991384138332 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 991384138332, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1467648000000).

991384138332 is an abundant number, since it is smaller than the sum of its proper divisors (1943911861668).

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

991384138332 is a wasteful number, since it uses less digits than its factorization.

991384138332 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1973 (or 1968 counting only the distinct ones).

The product of its digits is 3359232, while the sum is 54.

The spelling of 991384138332 in words is "nine hundred ninety-one billion, three hundred eighty-four million, one hundred thirty-eight thousand, three hundred thirty-two".