20425636 has 96 divisors (see below), whose sum is σ = 48771072. Its totient is φ = 7242240.

The previous prime is 20425607. The next prime is 20425637. The reversal of 20425636 is 63652402.

It is a happy number.

20425636 is a nontrivial binomial coefficient, being equal to C(6392, 2).

It is a Harshad number since it is a multiple of its sum of digits (28).

It is not an unprimeable number, because it can be changed into a prime (20425637) 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, 246051 + ... + 246133.

It is an arithmetic number, because the mean of its divisors is an integer number (508032).

Almost surely, 2^20425636 is an apocalyptic number.

20425636 is the 6391-st triangular number and also the 3196-th hexagonal number.

20425636 is the 2131-st centered nonagonal number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20425636, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24385536).

20425636 is an abundant number, since it is smaller than the sum of its proper divisors (28345436).

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

20425636 is a wasteful number, since it uses less digits than its factorization.

20425636 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 169 (or 167 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 28.

The square root of 20425636 is about 4519.4729781248. The cubic root of 20425636 is about 273.3538506642.

The spelling of 20425636 in words is "twenty million, four hundred twenty-five thousand, six hundred thirty-six".