4021729 has 4 divisors (see below), whose sum is σ = 4033476. Its totient is φ = 4009984.

The previous prime is 4021727. The next prime is 4021733. The reversal of 4021729 is 9271204.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 2331729 + 1690000 = 1527^2 + 1300^2 .

It is a cyclic number.

It is not a de Polignac number, because 4021729 - 2¹ = 4021727 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (4021727) 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, 5344 + ... + 6049.

It is an arithmetic number, because the mean of its divisors is an integer number (1008369).

Almost surely, 2^4021729 is an apocalyptic number.

It is an amenable number.

4021729 is a deficient number, since it is larger than the sum of its proper divisors (11747).

4021729 is a wasteful number, since it uses less digits than its factorization.

4021729 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11746.

The product of its (nonzero) digits is 1008, while the sum is 25.

The square root of 4021729 is about 2005.4248926350. The cubic root of 4021729 is about 159.0270249279.

The spelling of 4021729 in words is "four million, twenty-one thousand, seven hundred twenty-nine".