1261087539629 has 4 divisors (see below), whose sum is σ = 1295170986684. Its totient is φ = 1227004092576.

The previous prime is 1261087539623. The next prime is 1261087539659. The reversal of 1261087539629 is 9269357801621.

It is a happy number.

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

It can be written as a sum of positive squares in 2 ways, for example, as 545537346025 + 715550193604 = 738605^2 + 845902^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1261087539629 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 (1261087539623) 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, 17041723472 + ... + 17041723545.

It is an arithmetic number, because the mean of its divisors is an integer number (323792746671).

Almost surely, 2^{1261087539629} is an apocalyptic number.

It is an amenable number.

1261087539629 is a deficient number, since it is larger than the sum of its proper divisors (34083447055).

1261087539629 is an equidigital number, since it uses as much as digits as its factorization.

1261087539629 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34083447054.

The product of its (nonzero) digits is 9797760, while the sum is 59.

The spelling of 1261087539629 in words is "one trillion, two hundred sixty-one billion, eighty-seven million, five hundred thirty-nine thousand, six hundred twenty-nine".