2191167555851 has 2 divisors, whose sum is σ = 2191167555852. Its totient is φ = 2191167555850.

The previous prime is 2191167555833. The next prime is 2191167555877. The reversal of 2191167555851 is 1585557611912.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 2191167555851 - 2³⁸ = 1916289648907 is a prime.

It is not a weakly prime, because it can be changed into another prime (2191167555251) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1095583777925 + 1095583777926.

It is an arithmetic number, because the mean of its divisors is an integer number (1095583777926).

Almost surely, 2^{2191167555851} is an apocalyptic number.

2191167555851 is a deficient number, since it is larger than the sum of its proper divisors (1).

2191167555851 is an equidigital number, since it uses as much as digits as its factorization.

2191167555851 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3780000, while the sum is 56.

The spelling of 2191167555851 in words is "two trillion, one hundred ninety-one billion, one hundred sixty-seven million, five hundred fifty-five thousand, eight hundred fifty-one".