20520816 has 20 divisors (see below), whose sum is σ = 53012232. Its totient is φ = 6840256.

The previous prime is 20520809. The next prime is 20520821. The reversal of 20520816 is 61802502.

It is a super-2 number, since 2×20520816² = 842207778611712, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (24).

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 3 ways as a sum of consecutive naturals, for example, 213711 + ... + 213806.

Almost surely, 2^20520816 is an apocalyptic number.

It is an amenable number.

20520816 is an abundant number, since it is smaller than the sum of its proper divisors (32491416).

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

20520816 is a wasteful number, since it uses less digits than its factorization.

20520816 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 427528 (or 427522 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 24.

The square root of 20520816 is about 4529.9907284673. The cubic root of 20520816 is about 273.7777870503. Note that the first 4 decimals are identical.

The spelling of 20520816 in words is "twenty million, five hundred twenty thousand, eight hundred sixteen".