1292778191 has 2 divisors, whose sum is σ = 1292778192. Its totient is φ = 1292778190.

The previous prime is 1292778167. The next prime is 1292778217. The reversal of 1292778191 is 1918772921.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1292778191 - 2¹⁸ = 1292516047 is a prime.

It is a super-2 number, since 2×1292778191² = 3342550902250464962, which contains 22 as substring.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1292778131) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 646389095 + 646389096.

It is an arithmetic number, because the mean of its divisors is an integer number (646389096).

Almost surely, 2^1292778191 is an apocalyptic number.

1292778191 is a deficient number, since it is larger than the sum of its proper divisors (1).

1292778191 is an equidigital number, since it uses as much as digits as its factorization.

1292778191 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 127008, while the sum is 47.

The square root of 1292778191 is about 35955.2248080860. The cubic root of 1292778191 is about 1089.3681468290.

The spelling of 1292778191 in words is "one billion, two hundred ninety-two million, seven hundred seventy-eight thousand, one hundred ninety-one".