21138027 has 8 divisors (see below), whose sum is σ = 28205520. Its totient is φ = 14081280.

The previous prime is 21138023. The next prime is 21138053. The reversal of 21138027 is 72083112.

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

It is not a de Polignac number, because 21138027 - 2² = 21138023 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21137988 and 21138006.

It is not an unprimeable number, because it can be changed into a prime (21138023) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 5299 + ... + 8387.

It is an arithmetic number, because the mean of its divisors is an integer number (3525690).

Almost surely, 2^21138027 is an apocalyptic number.

21138027 is a deficient number, since it is larger than the sum of its proper divisors (7067493).

21138027 is a wasteful number, since it uses less digits than its factorization.

21138027 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5373.

The product of its (nonzero) digits is 672, while the sum is 24.

The square root of 21138027 is about 4597.6110100790. The cubic root of 21138027 is about 276.4955521631.

The spelling of 21138027 in words is "twenty-one million, one hundred thirty-eight thousand, twenty-seven".