521721051 has 12 divisors (see below), whose sum is σ = 698610552. Its totient is φ = 346329088.

The previous prime is 521721047. The next prime is 521721073. The reversal of 521721051 is 150127125.

It is not a de Polignac number, because 521721051 - 2² = 521721047 is a prime.

It is not an unprimeable number, because it can be changed into a prime (521721001) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 196831 + ... + 199463.

It is an arithmetic number, because the mean of its divisors is an integer number (58217546).

Almost surely, 2^521721051 is an apocalyptic number.

521721051 is a deficient number, since it is larger than the sum of its proper divisors (176889501).

521721051 is an equidigital number, since it uses as much as digits as its factorization.

521721051 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3150 (or 2893 counting only the distinct ones).

The product of its (nonzero) digits is 700, while the sum is 24.

The square root of 521721051 is about 22841.2138687943. The cubic root of 521721051 is about 805.0313381059.

Adding to 521721051 its reverse (150127125), we get a palindrome (671848176).

The spelling of 521721051 in words is "five hundred twenty-one million, seven hundred twenty-one thousand, fifty-one".