21875145 has 8 divisors (see below), whose sum is σ = 35000256. Its totient is φ = 11666736.

The previous prime is 21875143. The next prime is 21875153. The reversal of 21875145 is 54157812.

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

It is not a de Polignac number, because 21875145 - 2¹ = 21875143 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21875143) 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, 729157 + ... + 729186.

It is an arithmetic number, because the mean of its divisors is an integer number (4375032).

Almost surely, 2^21875145 is an apocalyptic number.

It is an amenable number.

21875145 is a deficient number, since it is larger than the sum of its proper divisors (13125111).

21875145 is a wasteful number, since it uses less digits than its factorization.

21875145 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1458351.

The product of its digits is 11200, while the sum is 33.

The square root of 21875145 is about 4677.0872345938. The cubic root of 21875145 is about 279.6728534614.

The spelling of 21875145 in words is "twenty-one million, eight hundred seventy-five thousand, one hundred forty-five".