1887866561 has 12 divisors (see below), whose sum is σ = 2196999792. Its totient is φ = 1617500808.

The previous prime is 1887866537. The next prime is 1887866569. The reversal of 1887866561 is 1656687881.

It is a happy number.

It is not a de Polignac number, because 1887866561 - 2¹⁸ = 1887604417 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 1887866497 and 1887866506.

It is not an unprimeable number, because it can be changed into a prime (1887866569) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 138686 + ... + 151688.

It is an arithmetic number, because the mean of its divisors is an integer number (183083316).

Almost surely, 2^1887866561 is an apocalyptic number.

It is an amenable number.

1887866561 is a deficient number, since it is larger than the sum of its proper divisors (309133231).

1887866561 is a wasteful number, since it uses less digits than its factorization.

1887866561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15980 (or 15973 counting only the distinct ones).

The product of its digits is 3870720, while the sum is 56.

The square root of 1887866561 is about 43449.5864307130. The cubic root of 1887866561 is about 1235.9202025772.

The spelling of 1887866561 in words is "one billion, eight hundred eighty-seven million, eight hundred sixty-six thousand, five hundred sixty-one".