20415500 has 96 divisors (see below), whose sum is σ = 53813760. Its totient is φ = 6609600.

The previous prime is 20415491. The next prime is 20415509. The reversal of 20415500 is 551402.

It is an interprime number because it is at equal distance from previous prime (20415491) and next prime (20415509).

It is not an unprimeable number, because it can be changed into a prime (20415509) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 66347 + ... + 66653.

It is an arithmetic number, because the mean of its divisors is an integer number (560560).

Almost surely, 2^20415500 is an apocalyptic number.

20415500 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20415500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26906880).

20415500 is an abundant number, since it is smaller than the sum of its proper divisors (33398260).

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

20415500 is a wasteful number, since it uses less digits than its factorization.

20415500 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 352 (or 340 counting only the distinct ones).

The product of its (nonzero) digits is 200, while the sum is 17.

The square root of 20415500 is about 4518.3514692861. The cubic root of 20415500 is about 273.3086268897.

Adding to 20415500 its reverse (551402), we get a palindrome (20966902).

The spelling of 20415500 in words is "twenty million, four hundred fifteen thousand, five hundred".