20541521 has 16 divisors (see below), whose sum is σ = 27581568. Its totient is φ = 14774400.

The previous prime is 20541511. The next prime is 20541523. The reversal of 20541521 is 12514502.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20541521 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20541493 and 20541502.

It is not an unprimeable number, because it can be changed into a prime (20541523) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9260 + ... + 11261.

It is an arithmetic number, because the mean of its divisors is an integer number (1723848).

Almost surely, 2^20541521 is an apocalyptic number.

It is an amenable number.

20541521 is a deficient number, since it is larger than the sum of its proper divisors (7040047).

20541521 is a wasteful number, since it uses less digits than its factorization.

20541521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20552.

The product of its (nonzero) digits is 400, while the sum is 20.

The square root of 20541521 is about 4532.2754770645. The cubic root of 20541521 is about 273.8698344567.

The spelling of 20541521 in words is "twenty million, five hundred forty-one thousand, five hundred twenty-one".