20506212 has 18 divisors (see below), whose sum is σ = 51835238. Its totient is φ = 6835392.

The previous prime is 20506201. The next prime is 20506243. The reversal of 20506212 is 21260502.

It can be written as a sum of positive squares in only one way, i.e., 16842816 + 3663396 = 4104^2 + 1914^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 284773 + ... + 284844.

Almost surely, 2^20506212 is an apocalyptic number.

It is an amenable number.

20506212 is an abundant number, since it is smaller than the sum of its proper divisors (31329026).

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

20506212 is a wasteful number, since it uses less digits than its factorization.

20506212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 569627 (or 569622 counting only the distinct ones).

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

The square root of 20506212 is about 4528.3785177478. The cubic root of 20506212 is about 273.7128253767.

Adding to 20506212 its reverse (21260502), we get a palindrome (41766714).

The spelling of 20506212 in words is "twenty million, five hundred six thousand, two hundred twelve".