2158638191 has 2 divisors, whose sum is σ = 2158638192. Its totient is φ = 2158638190.

The previous prime is 2158638161. The next prime is 2158638197. The reversal of 2158638191 is 1918368512.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 2158638191 - 2¹⁴ = 2158621807 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2158638197) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1079319095 + 1079319096.

It is an arithmetic number, because the mean of its divisors is an integer number (1079319096).

Almost surely, 2^2158638191 is an apocalyptic number.

2158638191 is a deficient number, since it is larger than the sum of its proper divisors (1).

2158638191 is an equidigital number, since it uses as much as digits as its factorization.

2158638191 is an evil number, because the sum of its binary digits is even.

The product of its digits is 103680, while the sum is 44.

The square root of 2158638191 is about 46461.1471123992. The cubic root of 2158638191 is about 1292.3890968572.

The spelling of 2158638191 in words is "two billion, one hundred fifty-eight million, six hundred thirty-eight thousand, one hundred ninety-one".