1261016646563 has 8 divisors (see below), whose sum is σ = 1265980796256. Its totient is φ = 1256053780800.

The previous prime is 1261016646541. The next prime is 1261016646581. The reversal of 1261016646563 is 3656466101621.

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 1261016646563 - 2⁶ = 1261016646499 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1261016646863) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1671473 + ... + 2305613.

It is an arithmetic number, because the mean of its divisors is an integer number (158247599532).

Almost surely, 2^{1261016646563} is an apocalyptic number.

1261016646563 is a deficient number, since it is larger than the sum of its proper divisors (4964149693).

1261016646563 is an equidigital number, since it uses as much as digits as its factorization.

1261016646563 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 641965.

The product of its (nonzero) digits is 933120, while the sum is 47.

The spelling of 1261016646563 in words is "one trillion, two hundred sixty-one billion, sixteen million, six hundred forty-six thousand, five hundred sixty-three".