20520566 has 16 divisors (see below), whose sum is σ = 34007040. Its totient is φ = 9208680.

The previous prime is 20520557. The next prime is 20520569. The reversal of 20520566 is 66502502.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20520569) 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, 4166 + ... + 7641.

It is an arithmetic number, because the mean of its divisors is an integer number (2125440).

Almost surely, 2^20520566 is an apocalyptic number.

20520566 is a deficient number, since it is larger than the sum of its proper divisors (13486474).

20520566 is a wasteful number, since it uses less digits than its factorization.

20520566 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11899.

The product of its (nonzero) digits is 3600, while the sum is 26.

The square root of 20520566 is about 4529.9631345078. The cubic root of 20520566 is about 273.7766752569.

The spelling of 20520566 in words is "twenty million, five hundred twenty thousand, five hundred sixty-six".