20500521 has 16 divisors (see below), whose sum is σ = 30201984. Its totient is φ = 12303104.

The previous prime is 20500511. The next prime is 20500523. The reversal of 20500521 is 12500502.

It is not a de Polignac number, because 20500521 - 2⁶ = 20500457 is a prime.

It is a super-2 number, since 2×20500521² = 840542722542882, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 20500521.

It is not an unprimeable number, because it can be changed into a prime (20500523) 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, 7566 + ... + 9911.

It is an arithmetic number, because the mean of its divisors is an integer number (1887624).

Almost surely, 2^20500521 is an apocalyptic number.

It is an amenable number.

20500521 is a deficient number, since it is larger than the sum of its proper divisors (9701463).

20500521 is a wasteful number, since it uses less digits than its factorization.

20500521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17520.

The product of its (nonzero) digits is 100, while the sum is 15.

The square root of 20500521 is about 4527.7501035282. The cubic root of 20500521 is about 273.6875022566.

The spelling of 20500521 in words is "twenty million, five hundred thousand, five hundred twenty-one".