21012063 has 8 divisors (see below), whose sum is σ = 28126128. Its totient is φ = 13953024.

The previous prime is 21012059. The next prime is 21012073. The reversal of 21012063 is 36021012.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21012063 - 2² = 21012059 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21012053) 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 7 ways as a sum of consecutive naturals, for example, 12856 + ... + 14397.

It is an arithmetic number, because the mean of its divisors is an integer number (3515766).

Almost surely, 2^21012063 is an apocalyptic number.

21012063 is a deficient number, since it is larger than the sum of its proper divisors (7114065).

21012063 is a wasteful number, since it uses less digits than its factorization.

21012063 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27513.

The product of its (nonzero) digits is 72, while the sum is 15.

The square root of 21012063 is about 4583.8916872020. The cubic root of 21012063 is about 275.9452343554.

Adding to 21012063 its reverse (36021012), we get a palindrome (57033075).

The spelling of 21012063 in words is "twenty-one million, twelve thousand, sixty-three".