2124721 has 4 divisors (see below), whose sum is σ = 2138944. Its totient is φ = 2110500.

The previous prime is 2124679. The next prime is 2124757. The reversal of 2124721 is 1274212.

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 2124721 - 2¹⁵ = 2091953 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2124761) 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, 6885 + ... + 7186.

It is an arithmetic number, because the mean of its divisors is an integer number (534736).

2^2124721 is an apocalyptic number.

It is an amenable number.

2124721 is a deficient number, since it is larger than the sum of its proper divisors (14223).

2124721 is a wasteful number, since it uses less digits than its factorization.

2124721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14222.

The product of its digits is 224, while the sum is 19.

The square root of 2124721 is about 1457.6422743595. The cubic root of 2124721 is about 128.5584527175.

Adding to 2124721 its reverse (1274212), we get a palindrome (3398933).

It can be divided in two parts, 21 and 24721, that added together give a palindrome (24742).

The spelling of 2124721 in words is "two million, one hundred twenty-four thousand, seven hundred twenty-one".