2191506894 has 32 divisors (see below), whose sum is σ = 4895271840. Its totient is φ = 726713856.

The previous prime is 2191506893. The next prime is 2191506899. The reversal of 2191506894 is 4986051912.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2191506893) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 94717 + ... + 115560.

It is an arithmetic number, because the mean of its divisors is an integer number (152977245).

Almost surely, 2^2191506894 is an apocalyptic number.

2191506894 is an abundant number, since it is smaller than the sum of its proper divisors (2703764946).

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

2191506894 is a wasteful number, since it uses less digits than its factorization.

2191506894 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 210481 (or 210475 counting only the distinct ones).

The product of its (nonzero) digits is 155520, while the sum is 45.

The square root of 2191506894 is about 46813.5332355933. The cubic root of 2191506894 is about 1298.9156429067.

The spelling of 2191506894 in words is "two billion, one hundred ninety-one million, five hundred six thousand, eight hundred ninety-four".