1991679744 has 144 divisors (see below), whose sum is σ = 5686571520. Its totient is φ = 616611840.

The previous prime is 1991679737. The next prime is 1991679797. The reversal of 1991679744 is 4479761991.

1991679744 is digitally balanced in base 4, because in such base it contains all the possibile digits an equal number of times.

It is a Smith number, since the sum of its digits (57) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1030459 + ... + 1032389.

It is an arithmetic number, because the mean of its divisors is an integer number (39490080).

Almost surely, 2^1991679744 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 1991679744, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2843285760).

1991679744 is an abundant number, since it is smaller than the sum of its proper divisors (3694891776).

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

1991679744 is a wasteful number, since it uses less digits than its factorization.

1991679744 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2046 (or 2032 counting only the distinct ones).

The product of its digits is 3429216, while the sum is 57.

The square root of 1991679744 is about 44628.2393110013. The cubic root of 1991679744 is about 1258.1714772194.

The spelling of 1991679744 in words is "one billion, nine hundred ninety-one million, six hundred seventy-nine thousand, seven hundred forty-four".