21150145 has 8 divisors (see below), whose sum is σ = 25439400. Its totient is φ = 16880640.

The previous prime is 21150139. The next prime is 21150163. The reversal of 21150145 is 54105112.

It can be written as a sum of positive squares in 4 ways, for example, as 1710864 + 19439281 = 1308^2 + 4409^2 .

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

It is not a de Polignac number, because 21150145 - 2⁵ = 21150113 is a prime.

It is an unprimeable number.

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, 2466 + ... + 6955.

It is an arithmetic number, because the mean of its divisors is an integer number (3179925).

Almost surely, 2^21150145 is an apocalyptic number.

It is an amenable number.

21150145 is a deficient number, since it is larger than the sum of its proper divisors (4289255).

21150145 is an equidigital number, since it uses as much as digits as its factorization.

21150145 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9875.

The product of its (nonzero) digits is 200, while the sum is 19.

The square root of 21150145 is about 4598.9286795948. The cubic root of 21150145 is about 276.5483784910.

Adding to 21150145 its reverse (54105112), we get a palindrome (75255257).

The spelling of 21150145 in words is "twenty-one million, one hundred fifty thousand, one hundred forty-five".