21875573 has 2 divisors, whose sum is σ = 21875574. Its totient is φ = 21875572.

The previous prime is 21875561. The next prime is 21875587. The reversal of 21875573 is 37557812.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19864849 + 2010724 = 4457^2 + 1418^2 .

It is a cyclic number.

It is not a de Polignac number, because 21875573 - 2¹⁰ = 21874549 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21875533) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10937786 + 10937787.

It is an arithmetic number, because the mean of its divisors is an integer number (10937787).

Almost surely, 2^21875573 is an apocalyptic number.

It is an amenable number.

21875573 is a deficient number, since it is larger than the sum of its proper divisors (1).

21875573 is an equidigital number, since it uses as much as digits as its factorization.

21875573 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 58800, while the sum is 38.

The square root of 21875573 is about 4677.1329893429. The cubic root of 21875573 is about 279.6746774372.

The spelling of 21875573 in words is "twenty-one million, eight hundred seventy-five thousand, five hundred seventy-three".