2191521166511 has 2 divisors, whose sum is σ = 2191521166512. Its totient is φ = 2191521166510.

The previous prime is 2191521166507. The next prime is 2191521166573. The reversal of 2191521166511 is 1156611251912.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 2191521166511 - 2² = 2191521166507 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2191521966511) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1095760583255 + 1095760583256.

It is an arithmetic number, because the mean of its divisors is an integer number (1095760583256).

Almost surely, 2^{2191521166511} is an apocalyptic number.

2191521166511 is a deficient number, since it is larger than the sum of its proper divisors (1).

2191521166511 is an equidigital number, since it uses as much as digits as its factorization.

2191521166511 is an evil number, because the sum of its binary digits is even.

The product of its digits is 32400, while the sum is 41.

The spelling of 2191521166511 in words is "two trillion, one hundred ninety-one billion, five hundred twenty-one million, one hundred sixty-six thousand, five hundred eleven".