1261155007680 has 56 divisors (see below), whose sum is σ = 4004167152432. Its totient is φ = 336308001792.

The previous prime is 1261155007667. The next prime is 1261155007691. The reversal of 1261155007680 is 867005511621.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 656850607 + ... + 656852526.

Almost surely, 2^{1261155007680} is an apocalyptic number.

1261155007680 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1261155007680 is an abundant number, since it is smaller than the sum of its proper divisors (2743012144752).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1261155007680 is a wasteful number, since it uses less digits than its factorization.

1261155007680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1313703153 (or 1313703143 counting only the distinct ones).

The product of its (nonzero) digits is 100800, while the sum is 42.

The spelling of 1261155007680 in words is "one trillion, two hundred sixty-one billion, one hundred fifty-five million, seven thousand, six hundred eighty".