991392606000 has 240 divisors, whose sum is σ = 3543132347040. Its totient is φ = 258222988800.

The previous prime is 991392605927. The next prime is 991392606019. The reversal of 991392606000 is 606293199.

It is a happy number.

991392606000 is a `hidden beast` number, since 9 + 9 + 1 + 39 + 2 + 6 + 0 + 600 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (240).

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 47 ways as a sum of consecutive naturals, for example, 133566 + ... + 1414434.

It is an arithmetic number, because the mean of its divisors is an integer number (14763051446).

Almost surely, 2^991392606000 is an apocalyptic number.

991392606000 is a gapful number since it is divisible by the number (90) 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 991392606000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1771566173520).

991392606000 is an abundant number, since it is smaller than the sum of its proper divisors (2551739741040).

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

991392606000 is a wasteful number, since it uses less digits than its factorization.

991392606000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1280941 (or 1280922 counting only the distinct ones).

The product of its (nonzero) digits is 157464, while the sum is 45.

Adding to 991392606000 its reverse (606293199), we get a palindrome (991998899199).

The spelling of 991392606000 in words is "nine hundred ninety-one billion, three hundred ninety-two million, six hundred six thousand".