1261729842753 has 4 divisors (see below), whose sum is σ = 1682306457008. Its totient is φ = 841153228500.

The previous prime is 1261729842749. The next prime is 1261729842799. The reversal of 1261729842753 is 3572489271621.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 1261729842753 - 2² = 1261729842749 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 1261729842693 and 1261729842702.

It is not an unprimeable number, because it can be changed into a prime (1261729842743) 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, 210288307123 + ... + 210288307128.

It is an arithmetic number, because the mean of its divisors is an integer number (420576614252).

Almost surely, 2^{1261729842753} is an apocalyptic number.

It is an amenable number.

1261729842753 is a deficient number, since it is larger than the sum of its proper divisors (420576614255).

1261729842753 is an equidigital number, since it uses as much as digits as its factorization.

1261729842753 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 420576614254.

The product of its digits is 10160640, while the sum is 57.

The spelling of 1261729842753 in words is "one trillion, two hundred sixty-one billion, seven hundred twenty-nine million, eight hundred forty-two thousand, seven hundred fifty-three".