2104121021 has 4 divisors (see below), whose sum is σ = 2153054112. Its totient is φ = 2055187932.

The previous prime is 2104121017. The next prime is 2104121101. The reversal of 2104121021 is 1201214012.

It is a happy number.

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 2104121021 - 2² = 2104121017 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 2104120987 and 2104121005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2104121221) 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, 24466481 + ... + 24466566.

It is an arithmetic number, because the mean of its divisors is an integer number (538263528).

Almost surely, 2^2104121021 is an apocalyptic number.

It is an amenable number.

2104121021 is a deficient number, since it is larger than the sum of its proper divisors (48933091).

2104121021 is an equidigital number, since it uses as much as digits as its factorization.

2104121021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 48933090.

The product of its (nonzero) digits is 32, while the sum is 14.

The square root of 2104121021 is about 45870.6989373391. The cubic root of 2104121021 is about 1281.4162832973.

Adding to 2104121021 its reverse (1201214012), we get a palindrome (3305335033).

The spelling of 2104121021 in words is "two billion, one hundred four million, one hundred twenty-one thousand, twenty-one".