21519145 has 8 divisors (see below), whose sum is σ = 26945856. Its totient is φ = 16466736.

The previous prime is 21519143. The next prime is 21519149. The reversal of 21519145 is 54191512.

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

It is a cyclic number.

It is not a de Polignac number, because 21519145 - 2¹ = 21519143 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21519143) 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, 93447 + ... + 93676.

It is an arithmetic number, because the mean of its divisors is an integer number (3368232).

Almost surely, 2^21519145 is an apocalyptic number.

It is an amenable number.

21519145 is a deficient number, since it is larger than the sum of its proper divisors (5426711).

21519145 is a wasteful number, since it uses less digits than its factorization.

21519145 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 187151.

The product of its digits is 1800, while the sum is 28.

The square root of 21519145 is about 4638.8732468133. The cubic root of 21519145 is about 278.1473995342.

The spelling of 21519145 in words is "twenty-one million, five hundred nineteen thousand, one hundred forty-five".