20121115 has 24 divisors (see below), whose sum is σ = 29745792. Its totient is φ = 12983040.

The previous prime is 20121107. The next prime is 20121121. The reversal of 20121115 is 51112102.

It is not a de Polignac number, because 20121115 - 2³ = 20121107 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20121095 and 20121104.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1750 + ... + 6580.

It is an arithmetic number, because the mean of its divisors is an integer number (1239408).

Almost surely, 2^20121115 is an apocalyptic number.

20121115 is a deficient number, since it is larger than the sum of its proper divisors (9624677).

20121115 is a wasteful number, since it uses less digits than its factorization.

20121115 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4867 (or 4860 counting only the distinct ones).

The product of its (nonzero) digits is 20, while the sum is 13.

The square root of 20121115 is about 4485.6565851612. The cubic root of 20121115 is about 271.9885871437.

Adding to 20121115 its reverse (51112102), we get a palindrome (71233217).

It can be divided in two parts, 201 and 21115, that added together give a square (21316 = 146²).

The spelling of 20121115 in words is "twenty million, one hundred twenty-one thousand, one hundred fifteen".