21115012 has 24 divisors (see below), whose sum is σ = 39606336. Its totient is φ = 9823968.

The previous prime is 21115007. The next prime is 21115013. The reversal of 21115012 is 21051112.

It is a junction number, because it is equal to n+sod(n) for n = 21114983 and 21115001.

It is not an unprimeable number, because it can be changed into a prime (21115013) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 303 + ... + 6505.

It is an arithmetic number, because the mean of its divisors is an integer number (1650264).

Almost surely, 2^21115012 is an apocalyptic number.

It is an amenable number.

21115012 is a deficient number, since it is larger than the sum of its proper divisors (18491324).

21115012 is a wasteful number, since it uses less digits than its factorization.

21115012 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6267 (or 6265 counting only the distinct ones).

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

The square root of 21115012 is about 4595.1073980920. The cubic root of 21115012 is about 276.3951666342.

Adding to 21115012 its reverse (21051112), we get a palindrome (42166124).

The spelling of 21115012 in words is "twenty-one million, one hundred fifteen thousand, twelve".