521611001 has 16 divisors (see below), whose sum is σ = 540440208. Its totient is φ = 503193600.

The previous prime is 521610977. The next prime is 521611007. The reversal of 521611001 is 100116125.

It can be written as a sum of positive squares in 8 ways, for example, as 9765625 + 511845376 = 3125^2 + 22624^2 .

It is a cyclic number.

It is not a de Polignac number, because 521611001 - 2⁶ = 521610937 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (521611007) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1238771 + ... + 1239191.

It is an arithmetic number, because the mean of its divisors is an integer number (33777513).

Almost surely, 2^521611001 is an apocalyptic number.

It is an amenable number.

521611001 is a deficient number, since it is larger than the sum of its proper divisors (18829207).

521611001 is a wasteful number, since it uses less digits than its factorization.

521611001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 812.

The product of its (nonzero) digits is 60, while the sum is 17.

The square root of 521611001 is about 22838.8047191616. The cubic root of 521611001 is about 804.9747306343.

Adding to 521611001 its reverse (100116125), we get a palindrome (621727126).

The spelling of 521611001 in words is "five hundred twenty-one million, six hundred eleven thousand, one".