1871622890561 has 4 divisors (see below), whose sum is σ = 1885284371652. Its totient is φ = 1857961409472.

The previous prime is 1871622890531. The next prime is 1871622890587. The reversal of 1871622890561 is 1650982261781.

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 528028942336 + 1343593948225 = 726656^2 + 1159135^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1871622890561 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1871622890497 and 1871622890506.

It is not an unprimeable number, because it can be changed into a prime (1871622890531) 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, 6830740340 + ... + 6830740613.

It is an arithmetic number, because the mean of its divisors is an integer number (471321092913).

Almost surely, 2^{1871622890561} is an apocalyptic number.

It is an amenable number.

1871622890561 is a deficient number, since it is larger than the sum of its proper divisors (13661481091).

1871622890561 is a wasteful number, since it uses less digits than its factorization.

1871622890561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13661481090.

The product of its (nonzero) digits is 2903040, while the sum is 56.

The spelling of 1871622890561 in words is "one trillion, eight hundred seventy-one billion, six hundred twenty-two million, eight hundred ninety thousand, five hundred sixty-one".