21150473 has 4 divisors (see below), whose sum is σ = 21179028. Its totient is φ = 21121920.

The previous prime is 21150443. The next prime is 21150487. The reversal of 21150473 is 37405112.

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

It can be written as a sum of positive squares in 2 ways, for example, as 238144 + 20912329 = 488^2 + 4573^2 .

It is a cyclic number.

It is not a de Polignac number, because 21150473 - 2¹⁰ = 21149449 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21150443) 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 3 ways as a sum of consecutive naturals, for example, 13136 + ... + 14657.

It is an arithmetic number, because the mean of its divisors is an integer number (5294757).

Almost surely, 2^21150473 is an apocalyptic number.

It is an amenable number.

21150473 is a deficient number, since it is larger than the sum of its proper divisors (28555).

21150473 is an equidigital number, since it uses as much as digits as its factorization.

21150473 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28554.

The product of its (nonzero) digits is 840, while the sum is 23.

The square root of 21150473 is about 4598.9643399357. The cubic root of 21150473 is about 276.5498080698.

Adding to 21150473 its reverse (37405112), we get a palindrome (58555585).

The spelling of 21150473 in words is "twenty-one million, one hundred fifty thousand, four hundred seventy-three".