20216161 has 16 divisors (see below), whose sum is σ = 24364800. Its totient is φ = 16406208.

The previous prime is 20216137. The next prime is 20216167. The reversal of 20216161 is 16161202.

It is not a de Polignac number, because 20216161 - 2⁷ = 20216033 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20216167) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9820 + ... + 11698.

It is an arithmetic number, because the mean of its divisors is an integer number (1522800).

Almost surely, 2^20216161 is an apocalyptic number.

It is an amenable number.

20216161 is a deficient number, since it is larger than the sum of its proper divisors (4148639).

20216161 is a wasteful number, since it uses less digits than its factorization.

20216161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1968.

The product of its (nonzero) digits is 144, while the sum is 19.

The square root of 20216161 is about 4496.2385390457. The cubic root of 20216161 is about 272.4161782421.

Adding to 20216161 its reverse (16161202), we get a palindrome (36377363).

The spelling of 20216161 in words is "twenty million, two hundred sixteen thousand, one hundred sixty-one".