3721121 has 4 divisors (see below), whose sum is σ = 3724992. Its totient is φ = 3717252.

The previous prime is 3721117. The next prime is 3721129. The reversal of 3721121 is 1211273.

3721121 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 1211273 = 7 ⋅173039.

It is a cyclic number.

It is not a de Polignac number, because 3721121 - 2² = 3721117 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 3721121.

It is not an unprimeable number, because it can be changed into a prime (3721129) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 740 + ... + 2826.

It is an arithmetic number, because the mean of its divisors is an integer number (931248).

Almost surely, 2^3721121 is an apocalyptic number.

It is an amenable number.

3721121 is a deficient number, since it is larger than the sum of its proper divisors (3871).

3721121 is a wasteful number, since it uses less digits than its factorization.

3721121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3870.

The product of its digits is 84, while the sum is 17.

The square root of 3721121 is about 1929.0207360213. The cubic root of 3721121 is about 154.9617803789.

Adding to 3721121 its reverse (1211273), we get a palindrome (4932394).

It can be divided in two parts, 3721 and 121, that multiplied together give a square (450241 = 671²).

The spelling of 3721121 in words is "three million, seven hundred twenty-one thousand, one hundred twenty-one".