991515605346 has 384 divisors, whose sum is σ = 2728008253440. Its totient is φ = 265764240000.

The previous prime is 991515605329. The next prime is 991515605351. The reversal of 991515605346 is 643506515199.

991515605346 is a `hidden beast` number, since 9 + 9 + 1 + 51 + 56 + 0 + 534 + 6 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a junction number, because it is equal to n+sod(n) for n = 991515605292 and 991515605301.

It is an unprimeable number.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 355253211 + ... + 355256001.

It is an arithmetic number, because the mean of its divisors is an integer number (7104188160).

Almost surely, 2^991515605346 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 991515605346, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1364004126720).

991515605346 is an abundant number, since it is smaller than the sum of its proper divisors (1736492648094).

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

991515605346 is a wasteful number, since it uses less digits than its factorization.

991515605346 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2979 (or 2966 counting only the distinct ones).

The product of its (nonzero) digits is 4374000, while the sum is 54.

The spelling of 991515605346 in words is "nine hundred ninety-one billion, five hundred fifteen million, six hundred five thousand, three hundred forty-six".