1261011685 has 12 divisors (see below), whose sum is σ = 1581869772. Its totient is φ = 964946048.

The previous prime is 1261011673. The next prime is 1261011691. The reversal of 1261011685 is 5861101621.

It can be written as a sum of positive squares in 2 ways, for example, as 496710369 + 764301316 = 22287^2 + 27646^2 .

It is not a de Polignac number, because 1261011685 - 2¹¹ = 1261009637 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 235732 + ... + 241021.

It is an arithmetic number, because the mean of its divisors is an integer number (131822481).

Almost surely, 2^1261011685 is an apocalyptic number.

It is an amenable number.

1261011685 is a deficient number, since it is larger than the sum of its proper divisors (320858087).

1261011685 is an equidigital number, since it uses as much as digits as its factorization.

1261011685 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 476804 (or 476781 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 31.

The square root of 1261011685 is about 35510.7263372632. The cubic root of 1261011685 is about 1080.3712958049.

The spelling of 1261011685 in words is "one billion, two hundred sixty-one million, eleven thousand, six hundred eighty-five".