20451204 has 120 divisors (see below), whose sum is σ = 58544640. Its totient is φ = 6200064.

The previous prime is 20451203. The next prime is 20451241. The reversal of 20451204 is 40215402.

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

It is not an unprimeable number, because it can be changed into a prime (20451203) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 258837 + ... + 258915.

It is an arithmetic number, because the mean of its divisors is an integer number (487872).

Almost surely, 2^20451204 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20451204, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29272320).

20451204 is an abundant number, since it is smaller than the sum of its proper divisors (38093436).

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

20451204 is a wasteful number, since it uses less digits than its factorization.

20451204 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 159 (or 148 counting only the distinct ones).

The product of its (nonzero) digits is 320, while the sum is 18.

The square root of 20451204 is about 4522.3007418791. The cubic root of 20451204 is about 273.4678609379.

Adding to 20451204 its reverse (40215402), we get a palindrome (60666606).

It can be divided in two parts, 2045 and 1204, that added together give a square (3249 = 57²).

The spelling of 20451204 in words is "twenty million, four hundred fifty-one thousand, two hundred four".