20920500 has 72 divisors (see below), whose sum is σ = 66011400. Its totient is φ = 5577600.

The previous prime is 20920483. The next prime is 20920511. The reversal of 20920500 is 502902.

It can be written as a sum of positive squares in 4 ways, for example, as 236196 + 20684304 = 486^2 + 4548^2 .

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2176 + ... + 6824.

It is an arithmetic number, because the mean of its divisors is an integer number (916825).

Almost surely, 2^20920500 is an apocalyptic number.

20920500 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 20920500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33005700).

20920500 is an abundant number, since it is smaller than the sum of its proper divisors (45090900).

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

20920500 is a wasteful number, since it uses less digits than its factorization.

20920500 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4674 (or 4659 counting only the distinct ones).

The product of its (nonzero) digits is 180, while the sum is 18.

The square root of 20920500 is about 4573.8933087688. The cubic root of 20920500 is about 275.5438274241.

The spelling of 20920500 in words is "twenty million, nine hundred twenty thousand, five hundred".