2043771821 has 24 divisors (see below), whose sum is σ = 2571146424. Its totient is φ = 1610219520.

The previous prime is 2043771799. The next prime is 2043771833. The reversal of 2043771821 is 1281773402.

It can be written as a sum of positive squares in 4 ways, for example, as 129709321 + 1914062500 = 11389^2 + 43750^2 .

It is not a de Polignac number, because 2043771821 - 2¹⁴ = 2043755437 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2043771871) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 146861 + ... + 160173.

It is an arithmetic number, because the mean of its divisors is an integer number (107131101).

Almost surely, 2^2043771821 is an apocalyptic number.

It is an amenable number.

2043771821 is a deficient number, since it is larger than the sum of its proper divisors (527374603).

2043771821 is a wasteful number, since it uses less digits than its factorization.

2043771821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13581 (or 13574 counting only the distinct ones).

The product of its (nonzero) digits is 18816, while the sum is 35.

The square root of 2043771821 is about 45208.0946402301. The cubic root of 2043771821 is about 1269.0463051115.

The spelling of 2043771821 in words is "two billion, forty-three million, seven hundred seventy-one thousand, eight hundred twenty-one".