2191723870434 has 128 divisors (see below), whose sum is σ = 5315540140032. Its totient is φ = 589126245120.

The previous prime is 2191723870433. The next prime is 2191723870463. The reversal of 2191723870434 is 4340783271912.

It is not an unprimeable number, because it can be changed into a prime (2191723870433) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 58416309 + ... + 58453815.

It is an arithmetic number, because the mean of its divisors is an integer number (41527657344).

Almost surely, 2^{2191723870434} is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 2191723870434, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2657770070016).

2191723870434 is an abundant number, since it is smaller than the sum of its proper divisors (3123816269598).

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

2191723870434 is a wasteful number, since it uses less digits than its factorization.

2191723870434 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38800.

The product of its (nonzero) digits is 2032128, while the sum is 51.

The spelling of 2191723870434 in words is "two trillion, one hundred ninety-one billion, seven hundred twenty-three million, eight hundred seventy thousand, four hundred thirty-four".