21540214093 has 2 divisors, whose sum is σ = 21540214094. Its totient is φ = 21540214092.

The previous prime is 21540214079. The next prime is 21540214103. The reversal of 21540214093 is 39041204512.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17444598084 + 4095616009 = 132078^2 + 63997^2 .

It is a cyclic number.

It is not a de Polignac number, because 21540214093 - 2⁹ = 21540213581 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21540214393) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10770107046 + 10770107047.

It is an arithmetic number, because the mean of its divisors is an integer number (10770107047).

Almost surely, 2^21540214093 is an apocalyptic number.

It is an amenable number.

21540214093 is a deficient number, since it is larger than the sum of its proper divisors (1).

21540214093 is an equidigital number, since it uses as much as digits as its factorization.

21540214093 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8640, while the sum is 31.

The spelling of 21540214093 in words is "twenty-one billion, five hundred forty million, two hundred fourteen thousand, ninety-three".