1261378017363 has 8 divisors (see below), whose sum is σ = 1685633830848. Its totient is φ = 839020441064.

The previous prime is 1261378017313. The next prime is 1261378017437. The reversal of 1261378017363 is 3637108731621.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1261378017363 - 2¹⁷ = 1261377886291 is a prime.

It is a super-2 number, since 2×1261378017363² (a number of 25 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1261378017313) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 474557745 + ... + 474560402.

It is an arithmetic number, because the mean of its divisors is an integer number (210704228856).

Almost surely, 2^{1261378017363} is an apocalyptic number.

1261378017363 is a deficient number, since it is larger than the sum of its proper divisors (424255813485).

1261378017363 is an equidigital number, since it uses as much as digits as its factorization.

1261378017363 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 949118593.

The product of its (nonzero) digits is 762048, while the sum is 48.

The spelling of 1261378017363 in words is "one trillion, two hundred sixty-one billion, three hundred seventy-eight million, seventeen thousand, three hundred sixty-three".