21710573 has 2 divisors, whose sum is σ = 21710574. Its totient is φ = 21710572.

The previous prime is 21710567. The next prime is 21710603. The reversal of 21710573 is 37501712.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21548164 + 162409 = 4642^2 + 403^2 .

It is a cyclic number.

It is not a de Polignac number, because 21710573 - 2⁸ = 21710317 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21710503) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10855286 + 10855287.

It is an arithmetic number, because the mean of its divisors is an integer number (10855287).

Almost surely, 2^21710573 is an apocalyptic number.

It is an amenable number.

21710573 is a deficient number, since it is larger than the sum of its proper divisors (1).

21710573 is an equidigital number, since it uses as much as digits as its factorization.

21710573 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1470, while the sum is 26.

The square root of 21710573 is about 4659.4605910985. The cubic root of 21710573 is about 278.9697384563.

The spelling of 21710573 in words is "twenty-one million, seven hundred ten thousand, five hundred seventy-three".