20021115 has 16 divisors (see below), whose sum is σ = 32560416. Its totient is φ = 10502400.

The previous prime is 20021093. The next prime is 20021137. The reversal of 20021115 is 51112002.

It is an interprime number because it is at equal distance from previous prime (20021093) and next prime (20021137).

It is not a de Polignac number, because 20021115 - 2¹⁴ = 20004731 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20021115.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10026 + ... + 11855.

It is an arithmetic number, because the mean of its divisors is an integer number (2035026).

Almost surely, 2^20021115 is an apocalyptic number.

20021115 is a deficient number, since it is larger than the sum of its proper divisors (12539301).

20021115 is a wasteful number, since it uses less digits than its factorization.

20021115 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21950.

The product of its (nonzero) digits is 20, while the sum is 12.

The square root of 20021115 is about 4474.4960610107. The cubic root of 20021115 is about 271.5372529424.

Adding to 20021115 its reverse (51112002), we get a palindrome (71133117).

The spelling of 20021115 in words is "twenty million, twenty-one thousand, one hundred fifteen".