1261678267 has 2 divisors, whose sum is σ = 1261678268. Its totient is φ = 1261678266.

The previous prime is 1261678259. The next prime is 1261678277. The reversal of 1261678267 is 7628761621.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1261678267 - 2³ = 1261678259 is a prime.

It is not a weakly prime, because it can be changed into another prime (1261678277) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 630839133 + 630839134.

It is an arithmetic number, because the mean of its divisors is an integer number (630839134).

Almost surely, 2^1261678267 is an apocalyptic number.

1261678267 is a deficient number, since it is larger than the sum of its proper divisors (1).

1261678267 is an equidigital number, since it uses as much as digits as its factorization.

1261678267 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 338688, while the sum is 46.

The square root of 1261678267 is about 35520.1107402553. The cubic root of 1261678267 is about 1080.5616268995.

The spelling of 1261678267 in words is "one billion, two hundred sixty-one million, six hundred seventy-eight thousand, two hundred sixty-seven".