991465738560 has 1344 divisors, whose sum is σ = 4026051993600. Its totient is φ = 230070067200.

The previous prime is 991465738513. The next prime is 991465738577. The reversal of 991465738560 is 65837564199.

991465738560 is a `hidden beast` number, since 9 + 9 + 1 + 4 + 6 + 573 + 8 + 56 + 0 = 666.

It is a super-3 number, since 3×991465738560³ (a number of 37 digits) contains 333 as substring.

It is a congruent number.

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, 3685746106 + ... + 3685746374.

It is an arithmetic number, because the mean of its divisors is an integer number (2995574400).

Almost surely, 2^991465738560 is an apocalyptic number.

991465738560 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 991465738560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2013025996800).

991465738560 is an abundant number, since it is smaller than the sum of its proper divisors (3034586255040).

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

991465738560 is a wasteful number, since it uses less digits than its factorization.

991465738560 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 482 (or 460 counting only the distinct ones).

The product of its (nonzero) digits is 48988800, while the sum is 63.

The spelling of 991465738560 in words is "nine hundred ninety-one billion, four hundred sixty-five million, seven hundred thirty-eight thousand, five hundred sixty".