1991442516 has 144 divisors (see below), whose sum is σ = 5716872000. Its totient is φ = 536481792.

The previous prime is 1991442503. The next prime is 1991442533. The reversal of 1991442516 is 6152441991.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 4435060 + ... + 4435508.

It is an arithmetic number, because the mean of its divisors is an integer number (39700500).

Almost surely, 2^1991442516 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 1991442516, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2858436000).

1991442516 is an abundant number, since it is smaller than the sum of its proper divisors (3725429484).

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

1991442516 is a wasteful number, since it uses less digits than its factorization.

1991442516 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 886 (or 877 counting only the distinct ones).

The product of its digits is 77760, while the sum is 42.

The square root of 1991442516 is about 44625.5814079772. The cubic root of 1991442516 is about 1258.1215218395.

The spelling of 1991442516 in words is "one billion, nine hundred ninety-one million, four hundred forty-two thousand, five hundred sixteen".