4038721 has 2 divisors, whose sum is σ = 4038722. Its totient is φ = 4038720.

The previous prime is 4038719. The next prime is 4038737. The reversal of 4038721 is 1278304.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 3459600 + 579121 = 1860^2 + 761^2 .

It is a cyclic number.

It is not a de Polignac number, because 4038721 - 2¹ = 4038719 is a prime.

It is a super-2 number, since 2×4038721² = 32622534631682, which contains 22 as substring.

Together with 4038719, it forms a pair of twin primes.

4038721 is a lucky number.

It is not a weakly prime, because it can be changed into another prime (4038701) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2019360 + 2019361.

It is an arithmetic number, because the mean of its divisors is an integer number (2019361).

Almost surely, 2^4038721 is an apocalyptic number.

It is an amenable number.

4038721 is a deficient number, since it is larger than the sum of its proper divisors (1).

4038721 is an equidigital number, since it uses as much as digits as its factorization.

4038721 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1344, while the sum is 25.

The square root of 4038721 is about 2009.6569358973. The cubic root of 4038721 is about 159.2506758743.

The spelling of 4038721 in words is "four million, thirty-eight thousand, seven hundred twenty-one".