2102440021 has 4 divisors (see below), whose sum is σ = 2293570944. Its totient is φ = 1911309100.

The previous prime is 2102440019. The next prime is 2102440037. The reversal of 2102440021 is 1200442012.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 2102440021 - 2¹ = 2102440019 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2102439977 and 2102440004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2102440121) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 95565445 + ... + 95565466.

It is an arithmetic number, because the mean of its divisors is an integer number (573392736).

Almost surely, 2^2102440021 is an apocalyptic number.

It is an amenable number.

2102440021 is a deficient number, since it is larger than the sum of its proper divisors (191130923).

2102440021 is a wasteful number, since it uses less digits than its factorization.

2102440021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 191130922.

The product of its (nonzero) digits is 128, while the sum is 16.

The square root of 2102440021 is about 45852.3720324260. The cubic root of 2102440021 is about 1281.0749476299.

Adding to 2102440021 its reverse (1200442012), we get a palindrome (3302882033).

The spelling of 2102440021 in words is "two billion, one hundred two million, four hundred forty thousand, twenty-one".