2191996837 has 4 divisors (see below), whose sum is σ = 2192499756. Its totient is φ = 2191493920.

The previous prime is 2191996787. The next prime is 2191996841. The reversal of 2191996837 is 7386991912.

2191996837 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 753008481 + 1438988356 = 27441^2 + 37934^2 .

It is a cyclic number.

It is not a de Polignac number, because 2191996837 - 2¹⁵ = 2191964069 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2191994837) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 244864 + ... + 253657.

It is an arithmetic number, because the mean of its divisors is an integer number (548124939).

Almost surely, 2^2191996837 is an apocalyptic number.

It is an amenable number.

2191996837 is a deficient number, since it is larger than the sum of its proper divisors (502919).

2191996837 is an equidigital number, since it uses as much as digits as its factorization.

2191996837 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 502918.

The product of its digits is 1469664, while the sum is 55.

The square root of 2191996837 is about 46818.7658637004. The cubic root of 2191996837 is about 1299.0124328079.

The spelling of 2191996837 in words is "two billion, one hundred ninety-one million, nine hundred ninety-six thousand, eight hundred thirty-seven".