2143905021 has 12 divisors (see below), whose sum is σ = 3097153020. Its totient is φ = 1429084800.

The previous prime is 2143905019. The next prime is 2143905053. The reversal of 2143905021 is 1205093412.

It can be written as a sum of positive squares in 2 ways, for example, as 1582925796 + 560979225 = 39786^2 + 23685^2 .

It is not a de Polignac number, because 2143905021 - 2¹ = 2143905019 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2143905091) 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, 129621 + ... + 145221.

It is an arithmetic number, because the mean of its divisors is an integer number (258096085).

Almost surely, 2^2143905021 is an apocalyptic number.

It is an amenable number.

2143905021 is a deficient number, since it is larger than the sum of its proper divisors (953247999).

2143905021 is a wasteful number, since it uses less digits than its factorization.

2143905021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30876 (or 30873 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 27.

The square root of 2143905021 is about 46302.3219828120. The cubic root of 2143905021 is about 1289.4421041694.

Adding to 2143905021 its reverse (1205093412), we get a palindrome (3348998433).

The spelling of 2143905021 in words is "two billion, one hundred forty-three million, nine hundred five thousand, twenty-one".