520635649 has 2 divisors, whose sum is σ = 520635650. Its totient is φ = 520635648.

The previous prime is 520635601. The next prime is 520635679. The reversal of 520635649 is 946536025.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 358837249 + 161798400 = 18943^2 + 12720^2 .

It is a cyclic number.

It is not a de Polignac number, because 520635649 - 2²¹ = 518538497 is a prime.

It is a super-2 number, since 2×520635649² = 542122958019302402, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (520635679) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 260317824 + 260317825.

It is an arithmetic number, because the mean of its divisors is an integer number (260317825).

Almost surely, 2^520635649 is an apocalyptic number.

It is an amenable number.

520635649 is a deficient number, since it is larger than the sum of its proper divisors (1).

520635649 is an equidigital number, since it uses as much as digits as its factorization.

520635649 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 194400, while the sum is 40.

The square root of 520635649 is about 22817.4417715922. The cubic root of 520635649 is about 804.4726811565.

It can be divided in two parts, 520635 and 649, that added together give a square (521284 = 722²).

The spelling of 520635649 in words is "five hundred twenty million, six hundred thirty-five thousand, six hundred forty-nine".