1261015126857 has 24 divisors (see below), whose sum is σ = 1917522609600. Its totient is φ = 796351821408.

The previous prime is 1261015126853. The next prime is 1261015126867. The reversal of 1261015126857 is 7586215101621.

1261015126857 is a `hidden beast` number, since 1 + 2 + 610 + 1 + 5 + 1 + 26 + 8 + 5 + 7 = 666.

It is not a de Polignac number, because 1261015126857 - 2² = 1261015126853 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1261015126853) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1393644 + ... + 2112882.

It is an arithmetic number, because the mean of its divisors is an integer number (79896775400).

Almost surely, 2^{1261015126857} is an apocalyptic number.

It is an amenable number.

1261015126857 is a deficient number, since it is larger than the sum of its proper divisors (656507482743).

1261015126857 is a wasteful number, since it uses less digits than its factorization.

1261015126857 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 729517 (or 729514 counting only the distinct ones).

The product of its (nonzero) digits is 201600, while the sum is 45.

The spelling of 1261015126857 in words is "one trillion, two hundred sixty-one billion, fifteen million, one hundred twenty-six thousand, eight hundred fifty-seven".