1287122455861 has 16 divisors (see below), whose sum is σ = 1465229191680. Its totient is φ = 1119201537520.

The previous prime is 1287122455859. The next prime is 1287122455889. The reversal of 1287122455861 is 1685542217821.

It is not a de Polignac number, because 1287122455861 - 2¹ = 1287122455859 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1287122455799 and 1287122455808.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1287122455561) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10891830 + ... + 11009368.

It is an arithmetic number, because the mean of its divisors is an integer number (91576824480).

Almost surely, 2^{1287122455861} is an apocalyptic number.

1287122455861 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1287122455861 is a deficient number, since it is larger than the sum of its proper divisors (178106735819).

1287122455861 is a wasteful number, since it uses less digits than its factorization.

1287122455861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 160856.

The product of its digits is 2150400, while the sum is 52.

The spelling of 1287122455861 in words is "one trillion, two hundred eighty-seven billion, one hundred twenty-two million, four hundred fifty-five thousand, eight hundred sixty-one".