20505516 has 48 divisors (see below), whose sum is σ = 49267680. Its totient is φ = 6635520.

The previous prime is 20505497. The next prime is 20505571. The reversal of 20505516 is 61550502.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 79660 + ... + 79916.

It is an arithmetic number, because the mean of its divisors is an integer number (1026410).

Almost surely, 2^20505516 is an apocalyptic number.

It is an amenable number.

20505516 is an abundant number, since it is smaller than the sum of its proper divisors (28762164).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20505516 is a wasteful number, since it uses less digits than its factorization.

20505516 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 434 (or 432 counting only the distinct ones).

The product of its (nonzero) digits is 1500, while the sum is 24.

The square root of 20505516 is about 4528.3016683962. The cubic root of 20505516 is about 273.7097286520.

The spelling of 20505516 in words is "twenty million, five hundred five thousand, five hundred sixteen".