521280761 has 2 divisors, whose sum is σ = 521280762. Its totient is φ = 521280760.

The previous prime is 521280733. The next prime is 521280791. The reversal of 521280761 is 167082125.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 451307536 + 69973225 = 21244^2 + 8365^2 .

It is a cyclic number.

It is not a de Polignac number, because 521280761 - 2¹⁴ = 521264377 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (521280731) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 260640380 + 260640381.

It is an arithmetic number, because the mean of its divisors is an integer number (260640381).

Almost surely, 2^521280761 is an apocalyptic number.

It is an amenable number.

521280761 is a deficient number, since it is larger than the sum of its proper divisors (1).

521280761 is an equidigital number, since it uses as much as digits as its factorization.

521280761 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6720, while the sum is 32.

The square root of 521280761 is about 22831.5737740525. The cubic root of 521280761 is about 804.8048141157.

The spelling of 521280761 in words is "five hundred twenty-one million, two hundred eighty thousand, seven hundred sixty-one".