2142857125861 has 4 divisors (see below), whose sum is σ = 2161820463372. Its totient is φ = 2123893788352.

The previous prime is 2142857125831. The next prime is 2142857125933. The reversal of 2142857125861 is 1685217582412.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 261817445761 + 1881039680100 = 511681^2 + 1371510^2 .

It is a cyclic number.

It is not a de Polignac number, because 2142857125861 - 2⁷ = 2142857125733 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2142857125799 and 2142857125808.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2142857125831) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9481668586 + ... + 9481668811.

It is an arithmetic number, because the mean of its divisors is an integer number (540455115843).

Almost surely, 2^{2142857125861} is an apocalyptic number.

It is an amenable number.

2142857125861 is a deficient number, since it is larger than the sum of its proper divisors (18963337511).

2142857125861 is a wasteful number, since it uses less digits than its factorization.

2142857125861 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18963337510.

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

The spelling of 2142857125861 in words is "two trillion, one hundred forty-two billion, eight hundred fifty-seven million, one hundred twenty-five thousand, eight hundred sixty-one".