1261516881771 has 48 divisors (see below), whose sum is σ = 1973887179264. Its totient is φ = 803610206784.

The previous prime is 1261516881767. The next prime is 1261516881773. The reversal of 1261516881771 is 1771886151621.

1261516881771 is a `hidden beast` number, since 1 + 2 + 615 + 1 + 6 + 8 + 8 + 17 + 7 + 1 = 666.

It is not a de Polignac number, because 1261516881771 - 2² = 1261516881767 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1261516881773) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 5287855 + ... + 5521271.

It is an arithmetic number, because the mean of its divisors is an integer number (41122649568).

Almost surely, 2^{1261516881771} is an apocalyptic number.

1261516881771 is a deficient number, since it is larger than the sum of its proper divisors (712370297493).

1261516881771 is an equidigital number, since it uses as much as digits as its factorization.

1261516881771 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 234422 (or 234410 counting only the distinct ones).

The product of its digits is 1128960, while the sum is 54.

The spelling of 1261516881771 in words is "one trillion, two hundred sixty-one billion, five hundred sixteen million, eight hundred eighty-one thousand, seven hundred seventy-one".