1261686167 has 4 divisors (see below), whose sum is σ = 1441927056. Its totient is φ = 1081445280.

The previous prime is 1261686157. The next prime is 1261686187. The reversal of 1261686167 is 7616861621.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1261686167 - 2²⁰ = 1260637591 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1261686157) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 90120434 + ... + 90120447.

It is an arithmetic number, because the mean of its divisors is an integer number (360481764).

Almost surely, 2^1261686167 is an apocalyptic number.

1261686167 is a deficient number, since it is larger than the sum of its proper divisors (180240889).

1261686167 is an equidigital number, since it uses as much as digits as its factorization.

1261686167 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 180240888.

The product of its digits is 145152, while the sum is 44.

The square root of 1261686167 is about 35520.2219446895. The cubic root of 1261686167 is about 1080.5638822074.

The spelling of 1261686167 in words is "one billion, two hundred sixty-one million, six hundred eighty-six thousand, one hundred sixty-seven".