21473417 has 6 divisors (see below), whose sum is σ = 24979338. Its totient is φ = 18405744.

The previous prime is 21473393. The next prime is 21473423. The reversal of 21473417 is 71437412.

It can be written as a sum of positive squares in only one way, i.e., 19571776 + 1901641 = 4424^2 + 1379^2 .

It is not a de Polignac number, because 21473417 - 2¹⁰ = 21472393 is a prime.

It is a super-2 number, since 2×21473417² = 922215275311778, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21473417.

It is not an unprimeable number, because it can be changed into a prime (21473437) 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 5 ways as a sum of consecutive naturals, for example, 219068 + ... + 219165.

It is an arithmetic number, because the mean of its divisors is an integer number (4163223).

Almost surely, 2^21473417 is an apocalyptic number.

It is an amenable number.

21473417 is a deficient number, since it is larger than the sum of its proper divisors (3505921).

21473417 is an equidigital number, since it uses as much as digits as its factorization.

21473417 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 438247 (or 438240 counting only the distinct ones).

The product of its digits is 4704, while the sum is 29.

The square root of 21473417 is about 4633.9418425354. The cubic root of 21473417 is about 277.9502395280.

The spelling of 21473417 in words is "twenty-one million, four hundred seventy-three thousand, four hundred seventeen".