21038473 has 4 divisors (see below), whose sum is σ = 21383428. Its totient is φ = 20693520.

The previous prime is 21038467. The next prime is 21038483. The reversal of 21038473 is 37483012.

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 11778624 + 9259849 = 3432^2 + 3043^2 .

It is a cyclic number.

It is not a de Polignac number, because 21038473 - 2⁵ = 21038441 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21038483) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 172386 + ... + 172507.

It is an arithmetic number, because the mean of its divisors is an integer number (5345857).

Almost surely, 2^21038473 is an apocalyptic number.

It is an amenable number.

21038473 is a deficient number, since it is larger than the sum of its proper divisors (344955).

21038473 is an equidigital number, since it uses as much as digits as its factorization.

21038473 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 344954.

The product of its (nonzero) digits is 4032, while the sum is 28.

The square root of 21038473 is about 4586.7715225418. The cubic root of 21038473 is about 276.0607975356.

It can be divided in two parts, 210 and 38473, that added together give a palindrome (38683).

The spelling of 21038473 in words is "twenty-one million, thirty-eight thousand, four hundred seventy-three".