21841573 has 4 divisors (see below), whose sum is σ = 23521708. Its totient is φ = 20161440.

The previous prime is 21841571. The next prime is 21841591. The reversal of 21841573 is 37514812.

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 10131489 + 11710084 = 3183^2 + 3422^2 .

It is not a de Polignac number, because 21841573 - 2¹ = 21841571 is a prime.

It is a super-2 number, since 2×21841573² = 954108622228658, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21841571) 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, 840048 + ... + 840073.

It is an arithmetic number, because the mean of its divisors is an integer number (5880427).

Almost surely, 2^21841573 is an apocalyptic number.

It is an amenable number.

21841573 is a deficient number, since it is larger than the sum of its proper divisors (1680135).

21841573 is a wasteful number, since it uses less digits than its factorization.

21841573 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1680134.

The product of its digits is 6720, while the sum is 31.

The square root of 21841573 is about 4673.4968706526. The cubic root of 21841573 is about 279.5297079820.

The spelling of 21841573 in words is "twenty-one million, eight hundred forty-one thousand, five hundred seventy-three".