521053821 has 6 divisors (see below), whose sum is σ = 752633310. Its totient is φ = 347369208.

The previous prime is 521053811. The next prime is 521053823. The reversal of 521053821 is 128350125.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 448973721 + 72080100 = 21189^2 + 8490^2 .

It is not a de Polignac number, because 521053821 - 2⁷ = 521053693 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (521053823) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 28947426 + ... + 28947443.

It is an arithmetic number, because the mean of its divisors is an integer number (125438885).

Almost surely, 2^521053821 is an apocalyptic number.

It is an amenable number.

521053821 is a deficient number, since it is larger than the sum of its proper divisors (231579489).

521053821 is a wasteful number, since it uses less digits than its factorization.

521053821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 57894875 (or 57894872 counting only the distinct ones).

The product of its (nonzero) digits is 2400, while the sum is 27.

The square root of 521053821 is about 22826.6033609909. The cubic root of 521053821 is about 804.6880063548.

The spelling of 521053821 in words is "five hundred twenty-one million, fifty-three thousand, eight hundred twenty-one".