2158278491 has 2 divisors, whose sum is σ = 2158278492. Its totient is φ = 2158278490.

The previous prime is 2158278431. The next prime is 2158278509. The reversal of 2158278491 is 1948728512.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 2158278491 - 2⁶ = 2158278427 is a prime.

It is a super-3 number, since 3×2158278491³ (a number of 29 digits) contains 333 as substring.

It is not a weakly prime, because it can be changed into another prime (2158278431) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1079139245 + 1079139246.

It is an arithmetic number, because the mean of its divisors is an integer number (1079139246).

Almost surely, 2^2158278491 is an apocalyptic number.

2158278491 is a deficient number, since it is larger than the sum of its proper divisors (1).

2158278491 is an equidigital number, since it uses as much as digits as its factorization.

2158278491 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 322560, while the sum is 47.

The square root of 2158278491 is about 46457.2759748137. The cubic root of 2158278491 is about 1292.3173080502.

The spelling of 2158278491 in words is "two billion, one hundred fifty-eight million, two hundred seventy-eight thousand, four hundred ninety-one".