20160021 has 12 divisors (see below), whose sum is σ = 31268832. Its totient is φ = 11519928.

The previous prime is 20160001. The next prime is 20160031. The reversal of 20160021 is 12006102.

It is not a de Polignac number, because 20160021 - 2⁶ = 20159957 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 20159979 and 20160006.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20160001) by changing a digit.

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 11 ways as a sum of consecutive naturals, for example, 68425 + ... + 68718.

It is an arithmetic number, because the mean of its divisors is an integer number (2605736).

Almost surely, 2^20160021 is an apocalyptic number.

20160021 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

20160021 is a deficient number, since it is larger than the sum of its proper divisors (11108811).

20160021 is a wasteful number, since it uses less digits than its factorization.

20160021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 137160 (or 137153 counting only the distinct ones).

The product of its (nonzero) digits is 24, while the sum is 12.

The square root of 20160021 is about 4489.9912026640. The cubic root of 20160021 is about 272.1637791394.

Adding to 20160021 its reverse (12006102), we get a palindrome (32166123).

The spelling of 20160021 in words is "twenty million, one hundred sixty thousand, twenty-one".