21004213093 has 2 divisors, whose sum is σ = 21004213094. Its totient is φ = 21004213092.

The previous prime is 21004213079. The next prime is 21004213151. The reversal of 21004213093 is 39031240012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 10642398244 + 10361814849 = 103162^2 + 101793^2 .

It is a cyclic number.

It is not a de Polignac number, because 21004213093 - 2²⁵ = 20970658661 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21004213033) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10502106546 + 10502106547.

It is an arithmetic number, because the mean of its divisors is an integer number (10502106547).

Almost surely, 2^21004213093 is an apocalyptic number.

It is an amenable number.

21004213093 is a deficient number, since it is larger than the sum of its proper divisors (1).

21004213093 is an equidigital number, since it uses as much as digits as its factorization.

21004213093 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1296, while the sum is 25.

The spelling of 21004213093 in words is "twenty-one billion, four million, two hundred thirteen thousand, ninety-three".