1261013325553 has 4 divisors (see below), whose sum is σ = 1264305788928. Its totient is φ = 1257720862180.

The previous prime is 1261013325461. The next prime is 1261013325571. The reversal of 1261013325553 is 3555233101621.

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 a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1261013325553 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1261013322553) 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, 1646231113 + ... + 1646231878.

It is an arithmetic number, because the mean of its divisors is an integer number (316076447232).

Almost surely, 2^{1261013325553} is an apocalyptic number.

It is an amenable number.

1261013325553 is a deficient number, since it is larger than the sum of its proper divisors (3292463375).

1261013325553 is an equidigital number, since it uses as much as digits as its factorization.

1261013325553 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3292463374.

The product of its (nonzero) digits is 81000, while the sum is 37.

The spelling of 1261013325553 in words is "one trillion, two hundred sixty-one billion, thirteen million, three hundred twenty-five thousand, five hundred fifty-three".