228761521 has 2 divisors, whose sum is σ = 228761522. Its totient is φ = 228761520.

The previous prime is 228761513. The next prime is 228761563. The reversal of 228761521 is 125167822.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 176358400 + 52403121 = 13280^2 + 7239^2 .

It is a cyclic number.

It is not a de Polignac number, because 228761521 - 2³ = 228761513 is a prime.

It is not a weakly prime, because it can be changed into another prime (228761021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 114380760 + 114380761.

It is an arithmetic number, because the mean of its divisors is an integer number (114380761).

Almost surely, 2^228761521 is an apocalyptic number.

It is an amenable number.

228761521 is a deficient number, since it is larger than the sum of its proper divisors (1).

228761521 is an equidigital number, since it uses as much as digits as its factorization.

228761521 is an evil number, because the sum of its binary digits is even.

The product of its digits is 13440, while the sum is 34.

The square root of 228761521 is about 15124.8643299700. The cubic root of 228761521 is about 611.5908675987.

The spelling of 228761521 in words is "two hundred twenty-eight million, seven hundred sixty-one thousand, five hundred twenty-one".