521313649 has 2 divisors, whose sum is σ = 521313650. Its totient is φ = 521313648.

The previous prime is 521313643. The next prime is 521313677. The reversal of 521313649 is 946313125.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 435473424 + 85840225 = 20868^2 + 9265^2 .

It is a cyclic number.

It is not a de Polignac number, because 521313649 - 2³ = 521313641 is a prime.

It is not a weakly prime, because it can be changed into another prime (521313641) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 260656824 + 260656825.

It is an arithmetic number, because the mean of its divisors is an integer number (260656825).

Almost surely, 2^521313649 is an apocalyptic number.

It is an amenable number.

521313649 is a deficient number, since it is larger than the sum of its proper divisors (1).

521313649 is an equidigital number, since it uses as much as digits as its factorization.

521313649 is an evil number, because the sum of its binary digits is even.

The product of its digits is 19440, while the sum is 34.

The square root of 521313649 is about 22832.2939933770. The cubic root of 521313649 is about 804.8217390092.

The spelling of 521313649 in words is "five hundred twenty-one million, three hundred thirteen thousand, six hundred forty-nine".