2104721 has 4 divisors (see below), whose sum is σ = 2153712. Its totient is φ = 2055732.

The previous prime is 2104717. The next prime is 2104723. The reversal of 2104721 is 1274012.

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 2104721 - 2² = 2104717 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 2104721.

It is not an unprimeable number, because it can be changed into a prime (2104723) 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, 24431 + ... + 24516.

It is an arithmetic number, because the mean of its divisors is an integer number (538428).

2^2104721 is an apocalyptic number.

It is an amenable number.

2104721 is a deficient number, since it is larger than the sum of its proper divisors (48991).

2104721 is an equidigital number, since it uses as much as digits as its factorization.

2104721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 48990.

The product of its (nonzero) digits is 112, while the sum is 17.

The square root of 2104721 is about 1450.7656599189. The cubic root of 2104721 is about 128.1538068085.

Adding to 2104721 its reverse (1274012), we get a palindrome (3378733).

The spelling of 2104721 in words is "two million, one hundred four thousand, seven hundred twenty-one".