21148147 has 4 divisors (see below), whose sum is σ = 21255696. Its totient is φ = 21040600.

The previous prime is 21148133. The next prime is 21148157. The reversal of 21148147 is 74184112.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21148147 - 2¹⁵ = 21115379 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21148157) 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 3 ways as a sum of consecutive naturals, for example, 53479 + ... + 53872.

It is an arithmetic number, because the mean of its divisors is an integer number (5313924).

Almost surely, 2^21148147 is an apocalyptic number.

21148147 is a deficient number, since it is larger than the sum of its proper divisors (107549).

21148147 is a wasteful number, since it uses less digits than its factorization.

21148147 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 107548.

The product of its digits is 1792, while the sum is 28.

The square root of 21148147 is about 4598.7114499607. The cubic root of 21148147 is about 276.5396699445.

The spelling of 21148147 in words is "twenty-one million, one hundred forty-eight thousand, one hundred forty-seven".