2238721 has 2 divisors, whose sum is σ = 2238722. Its totient is φ = 2238720.

The previous prime is 2238707. The next prime is 2238749. The reversal of 2238721 is 1278322.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1860496 + 378225 = 1364^2 + 615^2 .

It is a cyclic number.

It is not a de Polignac number, because 2238721 - 2⁹ = 2238209 is a prime.

It is a d-powerful number, because it can be written as 2⁸ + 2¹⁴ + 3¹⁰ + 8⁷ + 7³ + 2¹⁶ + 1 .

It is not a weakly prime, because it can be changed into another prime (2238791) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1119360 + 1119361.

It is an arithmetic number, because the mean of its divisors is an integer number (1119361).

2^2238721 is an apocalyptic number.

It is an amenable number.

2238721 is a deficient number, since it is larger than the sum of its proper divisors (1).

2238721 is an equidigital number, since it uses as much as digits as its factorization.

2238721 is an evil number, because the sum of its binary digits is even.

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

The square root of 2238721 is about 1496.2356097888. The cubic root of 2238721 is about 130.8177447270.

The spelling of 2238721 in words is "two million, two hundred thirty-eight thousand, seven hundred twenty-one".