20215500 has 48 divisors (see below), whose sum is σ = 58871904. Its totient is φ = 5390400.

The previous prime is 20215463. The next prime is 20215513. The reversal of 20215500 is 551202.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 20215500.

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, 5239 + ... + 8238.

It is an arithmetic number, because the mean of its divisors is an integer number (1226498).

Almost surely, 2^20215500 is an apocalyptic number.

20215500 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20215500 is an abundant number, since it is smaller than the sum of its proper divisors (38656404).

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

20215500 is a wasteful number, since it uses less digits than its factorization.

20215500 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13499 (or 13487 counting only the distinct ones).

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

The square root of 20215500 is about 4496.1650325583. The cubic root of 20215500 is about 272.4132091809.

Adding to 20215500 its reverse (551202), we get a palindrome (20766702).

The spelling of 20215500 in words is "twenty million, two hundred fifteen thousand, five hundred".