1687448447861 has 12 divisors (see below), whose sum is σ = 1854903319500. Its totient is φ = 1533957522240.

The previous prime is 1687448447831. The next prime is 1687448447873.

1687448447861 is nontrivially palindromic in base 10.

It can be written as a sum of positive squares in 2 ways, for example, as 471900302500 + 1215548145361 = 686950^2 + 1102519^2 .

It is a de Polignac number, because none of the positive numbers 2^k-1687448447861 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1687448447791 and 1687448447800.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1687448447821) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1811825 + ... + 2580233.

It is an arithmetic number, because the mean of its divisors is an integer number (154575276625).

Almost surely, 2^{1687448447861} is an apocalyptic number.

1687448447861 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1687448447861 is a deficient number, since it is larger than the sum of its proper divisors (167454871639).

1687448447861 is a wasteful number, since it uses less digits than its factorization.

1687448447861 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 786580 (or 786569 counting only the distinct ones).

The product of its digits is 231211008, while the sum is 68.

The spelling of 1687448447861 in words is "one trillion, six hundred eighty-seven billion, four hundred forty-eight million, four hundred forty-seven thousand, eight hundred sixty-one".