1267540886781 has 48 divisors (see below), whose sum is σ = 1985559816240. Its totient is φ = 774560517120.

The previous prime is 1267540886753. The next prime is 1267540886783. The reversal of 1267540886781 is 1876880457621.

It is a happy number.

1267540886781 is a `hidden beast` number, since 1 + 2 + 6 + 7 + 540 + 8 + 8 + 6 + 7 + 81 = 666.

It can be written as a sum of positive squares in 8 ways, for example, as 46239621156 + 1221301265625 = 215034^2 + 1105125^2 .

It is not a de Polignac number, because 1267540886781 - 2⁵ = 1267540886749 is a prime.

It is a super-2 number, since 2×1267540886781² (a number of 25 digits) contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1267540886783) 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, 29754865 + ... + 29797433.

It is an arithmetic number, because the mean of its divisors is an integer number (41365829505).

Almost surely, 2^{1267540886781} is an apocalyptic number.

It is an amenable number.

1267540886781 is a deficient number, since it is larger than the sum of its proper divisors (718018929459).

1267540886781 is a wasteful number, since it uses less digits than its factorization.

1267540886781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44366 (or 44363 counting only the distinct ones).

The product of its (nonzero) digits is 36126720, while the sum is 63.

The spelling of 1267540886781 in words is "one trillion, two hundred sixty-seven billion, five hundred forty million, eight hundred eighty-six thousand, seven hundred eighty-one".