20832521 has 4 divisors (see below), whose sum is σ = 21117972. Its totient is φ = 20547072.

The previous prime is 20832491. The next prime is 20832523. The reversal of 20832521 is 12523802.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12523802 = 2 ⋅6261901.

It can be written as a sum of positive squares in 2 ways, for example, as 4145296 + 16687225 = 2036^2 + 4085^2 .

It is a cyclic number.

It is not a de Polignac number, because 20832521 - 2¹⁸ = 20570377 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20832523) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 142616 + ... + 142761.

It is an arithmetic number, because the mean of its divisors is an integer number (5279493).

Almost surely, 2^20832521 is an apocalyptic number.

It is an amenable number.

20832521 is a deficient number, since it is larger than the sum of its proper divisors (285451).

20832521 is an equidigital number, since it uses as much as digits as its factorization.

20832521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 285450.

The product of its (nonzero) digits is 960, while the sum is 23.

The square root of 20832521 is about 4564.2656583507. The cubic root of 20832521 is about 275.1570276740.

The spelling of 20832521 in words is "twenty million, eight hundred thirty-two thousand, five hundred twenty-one".