1261338886 has 4 divisors (see below), whose sum is σ = 1892008332. Its totient is φ = 630669442.

The previous prime is 1261338857. The next prime is 1261338889. The reversal of 1261338886 is 6888331621.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 6888331621 = 373 ⋅18467377.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1261338889) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 315334720 + ... + 315334723.

It is an arithmetic number, because the mean of its divisors is an integer number (473002083).

Almost surely, 2^1261338886 is an apocalyptic number.

1261338886 is a deficient number, since it is larger than the sum of its proper divisors (630669446).

1261338886 is an equidigital number, since it uses as much as digits as its factorization.

1261338886 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 630669445.

The product of its digits is 331776, while the sum is 46.

The square root of 1261338886 is about 35515.3331112071. Note that the first 3 decimals coincide. The cubic root of 1261338886 is about 1080.4647308360.

The spelling of 1261338886 in words is "one billion, two hundred sixty-one million, three hundred thirty-eight thousand, eight hundred eighty-six".