3933721 has 4 divisors (see below), whose sum is σ = 4291344. Its totient is φ = 3576100.

The previous prime is 3933599. The next prime is 3933731. The reversal of 3933721 is 1273393.

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 an emirpimes, since its reverse is a distinct semiprime: 1273393 = 11 ⋅115763.

It is not a de Polignac number, because 3933721 - 2⁷ = 3933593 is a prime.

It is a Duffinian number.

3933721 is a lucky number.

It is a self number, because there is not a number n which added to its sum of digits gives 3933721.

It is not an unprimeable number, because it can be changed into a prime (3933731) 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, 178795 + ... + 178816.

It is an arithmetic number, because the mean of its divisors is an integer number (1072836).

Almost surely, 2^3933721 is an apocalyptic number.

It is an amenable number.

3933721 is a deficient number, since it is larger than the sum of its proper divisors (357623).

3933721 is a wasteful number, since it uses less digits than its factorization.

3933721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 357622.

The product of its digits is 3402, while the sum is 28.

The square root of 3933721 is about 1983.3610362211. The cubic root of 3933721 is about 157.8584562626.

It can be divided in two parts, 393 and 3721, that added together give a palindrome (4114).

The spelling of 3933721 in words is "three million, nine hundred thirty-three thousand, seven hundred twenty-one".