523400221 has 2 divisors, whose sum is σ = 523400222. Its totient is φ = 523400220.

The previous prime is 523400203. The next prime is 523400231. The reversal of 523400221 is 122004325.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 441588196 + 81812025 = 21014^2 + 9045^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-523400221 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (523400231) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 261700110 + 261700111.

It is an arithmetic number, because the mean of its divisors is an integer number (261700111).

Almost surely, 2^523400221 is an apocalyptic number.

It is an amenable number.

523400221 is a deficient number, since it is larger than the sum of its proper divisors (1).

523400221 is an equidigital number, since it uses as much as digits as its factorization.

523400221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 480, while the sum is 19.

The square root of 523400221 is about 22877.9417999085. The cubic root of 523400221 is about 805.8940831867.

Adding to 523400221 its reverse (122004325), we get a palindrome (645404546).

The spelling of 523400221 in words is "five hundred twenty-three million, four hundred thousand, two hundred twenty-one".