21542093 has 2 divisors, whose sum is σ = 21542094. Its totient is φ = 21542092.

The previous prime is 21542083. The next prime is 21542119. The reversal of 21542093 is 39024512.

It is an a-pointer prime, because the next prime (21542119) can be obtained adding 21542093 to its sum of digits (26).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20097289 + 1444804 = 4483^2 + 1202^2 .

It is a cyclic number.

It is not a de Polignac number, because 21542093 - 2¹⁶ = 21476557 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 (21542063) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10771046 + 10771047.

It is an arithmetic number, because the mean of its divisors is an integer number (10771047).

Almost surely, 2^21542093 is an apocalyptic number.

It is an amenable number.

21542093 is a deficient number, since it is larger than the sum of its proper divisors (1).

21542093 is an equidigital number, since it uses as much as digits as its factorization.

21542093 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2160, while the sum is 26.

The square root of 21542093 is about 4641.3460332106. The cubic root of 21542093 is about 278.2462364683.

The spelling of 21542093 in words is "twenty-one million, five hundred forty-two thousand, ninety-three".