2091978144 has 96 divisors (see below), whose sum is σ = 6179040000. Its totient is φ = 688476672.

The previous prime is 2091978139. The next prime is 2091978157. The reversal of 2091978144 is 4418791902.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (96).

It is a self number, because there is not a number n which added to its sum of digits gives 2091978144.

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, 52932 + ... + 83580.

It is an arithmetic number, because the mean of its divisors is an integer number (64365000).

Almost surely, 2^2091978144 is an apocalyptic number.

2091978144 is a gapful number since it is divisible by the number (24) 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 2091978144, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3089520000).

2091978144 is an abundant number, since it is smaller than the sum of its proper divisors (4087061856).

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

2091978144 is a wasteful number, since it uses less digits than its factorization.

2091978144 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30747 (or 30733 counting only the distinct ones).

The product of its (nonzero) digits is 145152, while the sum is 45.

The square root of 2091978144 is about 45738.1475794549. The cubic root of 2091978144 is about 1278.9465094757.

The spelling of 2091978144 in words is "two billion, ninety-one million, nine hundred seventy-eight thousand, one hundred forty-four".