521263261 has 2 divisors, whose sum is σ = 521263262. Its totient is φ = 521263260.

The previous prime is 521263213. The next prime is 521263273. The reversal of 521263261 is 162362125.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 487040761 + 34222500 = 22069^2 + 5850^2 .

It is a cyclic number.

It is not a de Polignac number, because 521263261 - 2⁷ = 521263133 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (521263861) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 260631630 + 260631631.

It is an arithmetic number, because the mean of its divisors is an integer number (260631631).

Almost surely, 2^521263261 is an apocalyptic number.

It is an amenable number.

521263261 is a deficient number, since it is larger than the sum of its proper divisors (1).

521263261 is an equidigital number, since it uses as much as digits as its factorization.

521263261 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4320, while the sum is 28.

The square root of 521263261 is about 22831.1905296242. The cubic root of 521263261 is about 804.7958079377.

The spelling of 521263261 in words is "five hundred twenty-one million, two hundred sixty-three thousand, two hundred sixty-one".