2105520521 has 8 divisors (see below), whose sum is σ = 2271167304. Its totient is φ = 1940400000.

The previous prime is 2105520517. The next prime is 2105520539. The reversal of 2105520521 is 1250255012.

It can be written as a sum of positive squares in 4 ways, for example, as 72863296 + 2032657225 = 8536^2 + 45085^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 2105520521 - 2² = 2105520517 is a prime.

It is a super-2 number, since 2×2105520521² = 8866433328704222882, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2105520821) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 123230 + ... + 139271.

It is an arithmetic number, because the mean of its divisors is an integer number (283895913).

Almost surely, 2^2105520521 is an apocalyptic number.

It is an amenable number.

2105520521 is a deficient number, since it is larger than the sum of its proper divisors (165646783).

2105520521 is a wasteful number, since it uses less digits than its factorization.

2105520521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 263131.

The product of its (nonzero) digits is 1000, while the sum is 23.

The square root of 2105520521 is about 45885.9512378244. The cubic root of 2105520521 is about 1281.7003202926.

Adding to 2105520521 its reverse (1250255012), we get a palindrome (3355775533).

The spelling of 2105520521 in words is "two billion, one hundred five million, five hundred twenty thousand, five hundred twenty-one".