20451136 has 28 divisors (see below), whose sum is σ = 42972228. Its totient is φ = 9623552.

The previous prime is 20451131. The next prime is 20451181. The reversal of 20451136 is 63115402.

It can be written as a sum of positive squares in 2 ways, for example, as 16451136 + 4000000 = 4056^2 + 2000^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20451131) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8311 + ... + 10486.

Almost surely, 2^20451136 is an apocalyptic number.

It is an amenable number.

20451136 is an abundant number, since it is smaller than the sum of its proper divisors (22521092).

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

20451136 is a wasteful number, since it uses less digits than its factorization.

20451136 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18826 (or 18816 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 22.

The square root of 20451136 is about 4522.2932235758. The cubic root of 20451136 is about 273.4675578451.

Adding to 20451136 its reverse (63115402), we get a palindrome (83566538).

The spelling of 20451136 in words is "twenty million, four hundred fifty-one thousand, one hundred thirty-six".