21045012 has 24 divisors (see below), whose sum is σ = 49286496. Its totient is φ = 6989088.

The previous prime is 21044999. The next prime is 21045041. The reversal of 21045012 is 21054012.

It is a junction number, because it is equal to n+sod(n) for n = 21044982 and 21045000.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 298 + ... + 6494.

It is an arithmetic number, because the mean of its divisors is an integer number (2053604).

Almost surely, 2^21045012 is an apocalyptic number.

It is an amenable number.

21045012 is an abundant number, since it is smaller than the sum of its proper divisors (28241484).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21045012 is a wasteful number, since it uses less digits than its factorization.

21045012 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6487 (or 6485 counting only the distinct ones).

The product of its (nonzero) digits is 80, while the sum is 15.

The square root of 21045012 is about 4587.4842779022. The cubic root of 21045012 is about 276.0893955326.

Adding to 21045012 its reverse (21054012), we get a palindrome (42099024).

The spelling of 21045012 in words is "twenty-one million, forty-five thousand, twelve".