20631216 has 20 divisors (see below), whose sum is σ = 53297432. Its totient is φ = 6877056.

The previous prime is 20631203. The next prime is 20631229. The reversal of 20631216 is 61213602.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (20631203) and next prime (20631229).

It is a junction number, because it is equal to n+sod(n) for n = 20631192 and 20631201.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 214861 + ... + 214956.

Almost surely, 2^20631216 is an apocalyptic number.

It is an amenable number.

20631216 is an abundant number, since it is smaller than the sum of its proper divisors (32666216).

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

20631216 is a wasteful number, since it uses less digits than its factorization.

20631216 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 429828 (or 429822 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 21.

The square root of 20631216 is about 4542.1598386671. The cubic root of 20631216 is about 274.2678752039.

Adding to 20631216 its reverse (61213602), we get a palindrome (81844818).

The spelling of 20631216 in words is "twenty million, six hundred thirty-one thousand, two hundred sixteen".