509947261 has 2 divisors, whose sum is σ = 509947262. Its totient is φ = 509947260.

The previous prime is 509947253. The next prime is 509947297. The reversal of 509947261 is 162749905.

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., 384395236 + 125552025 = 19606^2 + 11205^2 .

It is a cyclic number.

It is not a de Polignac number, because 509947261 - 2³ = 509947253 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (509947211) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 254973630 + 254973631.

It is an arithmetic number, because the mean of its divisors is an integer number (254973631).

Almost surely, 2^509947261 is an apocalyptic number.

It is an amenable number.

509947261 is a deficient number, since it is larger than the sum of its proper divisors (1).

509947261 is an equidigital number, since it uses as much as digits as its factorization.

509947261 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 136080, while the sum is 43.

The square root of 509947261 is about 22582.0118899978. The cubic root of 509947261 is about 798.9294331014.

The spelling of 509947261 in words is "five hundred nine million, nine hundred forty-seven thousand, two hundred sixty-one".