1261242043663 has 16 divisors (see below), whose sum is σ = 1443173193216. Its totient is φ = 1079749772640.

The previous prime is 1261242043661. The next prime is 1261242043681. The reversal of 1261242043663 is 3663402421621.

It is not a de Polignac number, because 1261242043663 - 2¹ = 1261242043661 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 (1261242043661) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 41346445 + ... + 41376937.

It is an arithmetic number, because the mean of its divisors is an integer number (90198324576).

Almost surely, 2^{1261242043663} is an apocalyptic number.

1261242043663 is a deficient number, since it is larger than the sum of its proper divisors (181931149553).

1261242043663 is an equidigital number, since it uses as much as digits as its factorization.

1261242043663 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37494.

The product of its (nonzero) digits is 248832, while the sum is 40.

The spelling of 1261242043663 in words is "one trillion, two hundred sixty-one billion, two hundred forty-two million, forty-three thousand, six hundred sixty-three".