991503781104 has 160 divisors (see below), whose sum is σ = 2706990741504. Its totient is φ = 312087381760.

The previous prime is 991503781097. The next prime is 991503781133. The reversal of 991503781104 is 401187305199.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 152747299 + ... + 152753789.

Almost surely, 2^991503781104 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 991503781104, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1353495370752).

991503781104 is an abundant number, since it is smaller than the sum of its proper divisors (1715486960400).

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

991503781104 is a wasteful number, since it uses less digits than its factorization.

991503781104 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8275 (or 8269 counting only the distinct ones).

The product of its (nonzero) digits is 272160, while the sum is 48.

The spelling of 991503781104 in words is "nine hundred ninety-one billion, five hundred three million, seven hundred eighty-one thousand, one hundred four".