2190974185891 has 2 divisors, whose sum is σ = 2190974185892. Its totient is φ = 2190974185890.

The previous prime is 2190974185889. The next prime is 2190974185909. The reversal of 2190974185891 is 1985814790912.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 2190974185891 - 2¹ = 2190974185889 is a prime.

Together with 2190974185889, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (2190974185691) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1095487092945 + 1095487092946.

It is an arithmetic number, because the mean of its divisors is an integer number (1095487092946).

Almost surely, 2^{2190974185891} is an apocalyptic number.

2190974185891 is a deficient number, since it is larger than the sum of its proper divisors (1).

2190974185891 is an equidigital number, since it uses as much as digits as its factorization.

2190974185891 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 13063680, while the sum is 64.

The spelling of 2190974185891 in words is "two trillion, one hundred ninety billion, nine hundred seventy-four million, one hundred eighty-five thousand, eight hundred ninety-one".