20425284 has 90 divisors (see below), whose sum is σ = 58803822. Its totient is φ = 6177600.

The previous prime is 20425277. The next prime is 20425289. The reversal of 20425284 is 48252402.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 15681600 + 4743684 = 3960^2 + 2178^2 .

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (20425289) by changing a digit.

It is a polite number, since it can be written in 29 ways as a sum of consecutive naturals, for example, 38944 + ... + 39464.

Almost surely, 2^20425284 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 20425284, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29401911).

20425284 is an abundant number, since it is smaller than the sum of its proper divisors (38378538).

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

20425284 is a wasteful number, since it uses less digits than its factorization.

20425284 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 559 (or 537 counting only the distinct ones).

The product of its (nonzero) digits is 5120, while the sum is 27.

The square root of 20425284 is about 4519.4340353633. The cubic root of 20425284 is about 273.3522803972.

Adding to 20425284 its reverse (48252402), we get a palindrome (68677686).

The spelling of 20425284 in words is "twenty million, four hundred twenty-five thousand, two hundred eighty-four".