1261686786 has 16 divisors (see below), whose sum is σ = 2525088384. Its totient is φ = 420276464.

The previous prime is 1261686761. The next prime is 1261686787. The reversal of 1261686786 is 6876861621.

It is not an unprimeable number, because it can be changed into a prime (1261686787) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 61785 + ... + 79628.

It is an arithmetic number, because the mean of its divisors is an integer number (157818024).

Almost surely, 2^1261686786 is an apocalyptic number.

1261686786 is an abundant number, since it is smaller than the sum of its proper divisors (1263401598).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1261686786 is a wasteful number, since it uses less digits than its factorization.

1261686786 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 142905.

The product of its digits is 1161216, while the sum is 51.

The square root of 1261686786 is about 35520.2306580349. The cubic root of 1261686786 is about 1080.5640589204.

The spelling of 1261686786 in words is "one billion, two hundred sixty-one million, six hundred eighty-six thousand, seven hundred eighty-six".