20527821 has 6 divisors (see below), whose sum is σ = 29651310. Its totient is φ = 13685208.

The previous prime is 20527817. The next prime is 20527849. The reversal of 20527821 is 12872502.

It can be written as a sum of positive squares in only one way, i.e., 13793796 + 6734025 = 3714^2 + 2595^2 .

It is not a de Polignac number, because 20527821 - 2² = 20527817 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20527421) 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, 1140426 + ... + 1140443.

It is an arithmetic number, because the mean of its divisors is an integer number (4941885).

Almost surely, 2^20527821 is an apocalyptic number.

It is an amenable number.

20527821 is a deficient number, since it is larger than the sum of its proper divisors (9123489).

20527821 is a wasteful number, since it uses less digits than its factorization.

20527821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2280875 (or 2280872 counting only the distinct ones).

The product of its (nonzero) digits is 2240, while the sum is 27.

The square root of 20527821 is about 4530.7638428857. The cubic root of 20527821 is about 273.8089358314.

The spelling of 20527821 in words is "twenty million, five hundred twenty-seven thousand, eight hundred twenty-one".