1887617696821 has 2 divisors, whose sum is σ = 1887617696822. Its totient is φ = 1887617696820.

The previous prime is 1887617696747. The next prime is 1887617696843. The reversal of 1887617696821 is 1286967167881.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1275758955025 + 611858741796 = 1129495^2 + 782214^2 .

It is a cyclic number.

It is not a de Polignac number, because 1887617696821 - 2¹⁹ = 1887617172533 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1887617690821) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 943808848410 + 943808848411.

It is an arithmetic number, because the mean of its divisors is an integer number (943808848411).

Almost surely, 2^{1887617696821} is an apocalyptic number.

It is an amenable number.

1887617696821 is a deficient number, since it is larger than the sum of its proper divisors (1).

1887617696821 is an equidigital number, since it uses as much as digits as its factorization.

1887617696821 is an evil number, because the sum of its binary digits is even.

The product of its digits is 97542144, while the sum is 70.

The spelling of 1887617696821 in words is "one trillion, eight hundred eighty-seven billion, six hundred seventeen million, six hundred ninety-six thousand, eight hundred twenty-one".