228040721 has 2 divisors, whose sum is σ = 228040722. Its totient is φ = 228040720.

The previous prime is 228040693. The next prime is 228040727. The reversal of 228040721 is 127040822.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 220938496 + 7102225 = 14864^2 + 2665^2 .

It is a cyclic number.

It is not a de Polignac number, because 228040721 - 2¹⁰ = 228039697 is a prime.

It is not a weakly prime, because it can be changed into another prime (228040727) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 114020360 + 114020361.

It is an arithmetic number, because the mean of its divisors is an integer number (114020361).

Almost surely, 2^228040721 is an apocalyptic number.

It is an amenable number.

228040721 is a deficient number, since it is larger than the sum of its proper divisors (1).

228040721 is an equidigital number, since it uses as much as digits as its factorization.

228040721 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1792, while the sum is 26.

The square root of 228040721 is about 15101.0172173930. The cubic root of 228040721 is about 610.9478420390.

The spelling of 228040721 in words is "two hundred twenty-eight million, forty thousand, seven hundred twenty-one".