20506224 has 20 divisors (see below), whose sum is σ = 52974536. Its totient is φ = 6835392.

The previous prime is 20506201. The next prime is 20506243. The reversal of 20506224 is 42260502.

It is a self number, because there is not a number n which added to its sum of digits gives 20506224.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 213559 + ... + 213654.

Almost surely, 2^20506224 is an apocalyptic number.

20506224 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

20506224 is an abundant number, since it is smaller than the sum of its proper divisors (32468312).

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

20506224 is a wasteful number, since it uses less digits than its factorization.

20506224 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 427224 (or 427218 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 21.

The square root of 20506224 is about 4528.3798427252. The cubic root of 20506224 is about 273.7128787679.

Adding to 20506224 its reverse (42260502), we get a palindrome (62766726).

The spelling of 20506224 in words is "twenty million, five hundred six thousand, two hundred twenty-four".