4040721 has 6 divisors (see below), whose sum is σ = 5836610. Its totient is φ = 2693808.

The previous prime is 4040719. The next prime is 4040723. The reversal of 4040721 is 1270404.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (4040719) and next prime (4040723).

It can be written as a sum of positive squares in only one way, i.e., 3294225 + 746496 = 1815^2 + 864^2 .

It is not a de Polignac number, because 4040721 - 2¹ = 4040719 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 4040694 and 4040703.

It is not an unprimeable number, because it can be changed into a prime (4040723) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 224476 + ... + 224493.

Almost surely, 2^4040721 is an apocalyptic number.

It is an amenable number.

4040721 is a deficient number, since it is larger than the sum of its proper divisors (1795889).

4040721 is a wasteful number, since it uses less digits than its factorization.

4040721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 448975 (or 448972 counting only the distinct ones).

The product of its (nonzero) digits is 224, while the sum is 18.

The square root of 4040721 is about 2010.1544716762. The cubic root of 4040721 is about 159.2769588478.

It can be divided in two parts, 4040 and 721, that added together give a square (4761 = 69²).

The spelling of 4040721 in words is "four million, forty thousand, seven hundred twenty-one".