20021625 has 72 divisors (see below), whose sum is σ = 39947544. Its totient is φ = 9590400.

The previous prime is 20021623. The next prime is 20021641. The reversal of 20021625 is 52612002.

20021625 = 865² + 866² + ... + 890².

20021625 is a `hidden beast` number, since 20 + 0 + 21 + 625 = 666.

It can be written as a sum of positive squares in 12 ways, for example, as 9072144 + 10949481 = 3012^2 + 3309^2 .

It is not a de Polignac number, because 20021625 - 2¹ = 20021623 is a prime.

20021625 is a Rhonda number in base 14.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 20021598 and 20021607.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20021623) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 541107 + ... + 541143.

It is an arithmetic number, because the mean of its divisors is an integer number (554827).

Almost surely, 2^20021625 is an apocalyptic number.

20021625 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

20021625 is a deficient number, since it is larger than the sum of its proper divisors (19925919).

20021625 is a wasteful number, since it uses less digits than its factorization.

20021625 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 108 (or 58 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 18.

The square root of 20021625 is about 4474.5530503057. The cubic root of 20021625 is about 271.5395585553.

Adding to 20021625 its reverse (52612002), we get a palindrome (72633627).

The spelling of 20021625 in words is "twenty million, twenty-one thousand, six hundred twenty-five".