21703541 has 2 divisors, whose sum is σ = 21703542. Its totient is φ = 21703540.

The previous prime is 21703501. The next prime is 21703573. The reversal of 21703541 is 14530712.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17098225 + 4605316 = 4135^2 + 2146^2 .

It is a cyclic number.

It is not a de Polignac number, because 21703541 - 2¹⁰ = 21702517 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21703501) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10851770 + 10851771.

It is an arithmetic number, because the mean of its divisors is an integer number (10851771).

Almost surely, 2^21703541 is an apocalyptic number.

It is an amenable number.

21703541 is a deficient number, since it is larger than the sum of its proper divisors (1).

21703541 is an equidigital number, since it uses as much as digits as its factorization.

21703541 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 840, while the sum is 23.

The square root of 21703541 is about 4658.7059362016. The cubic root of 21703541 is about 278.9396160050.

The spelling of 21703541 in words is "twenty-one million, seven hundred three thousand, five hundred forty-one".