1887438841821 has 12 divisors (see below), whose sum is σ = 2936015976348. Its totient is φ = 1161500825664.

The previous prime is 1887438841721. The next prime is 1887438841853. The reversal of 1887438841821 is 1281488347881.

1887438841821 is a `hidden beast` number, since 1 + 8 + 8 + 74 + 388 + 4 + 182 + 1 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 1114470819225 + 772968022596 = 1055685^2 + 879186^2 .

It is not a de Polignac number, because 1887438841821 - 2²³ = 1887430453213 is a prime.

It is a super-2 number, since 2×1887438841821² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1887438841891) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 8065977840 + ... + 8065978073.

It is an arithmetic number, because the mean of its divisors is an integer number (244667998029).

Almost surely, 2^{1887438841821} is an apocalyptic number.

It is an amenable number.

1887438841821 is a deficient number, since it is larger than the sum of its proper divisors (1048577134527).

1887438841821 is a wasteful number, since it uses less digits than its factorization.

1887438841821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16131955932 (or 16131955929 counting only the distinct ones).

The product of its digits is 22020096, while the sum is 63.

The spelling of 1887438841821 in words is "one trillion, eight hundred eighty-seven billion, four hundred thirty-eight million, eight hundred forty-one thousand, eight hundred twenty-one".