21549772093 has 2 divisors, whose sum is σ = 21549772094. Its totient is φ = 21549772092.

The previous prime is 21549772091. The next prime is 21549772117. The reversal of 21549772093 is 39027794512.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21518836249 + 30935844 = 146693^2 + 5562^2 .

It is a cyclic number.

It is not a de Polignac number, because 21549772093 - 2¹ = 21549772091 is a prime.

Together with 21549772091, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21549772091) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10774886046 + 10774886047.

It is an arithmetic number, because the mean of its divisors is an integer number (10774886047).

Almost surely, 2^21549772093 is an apocalyptic number.

It is an amenable number.

21549772093 is a deficient number, since it is larger than the sum of its proper divisors (1).

21549772093 is an equidigital number, since it uses as much as digits as its factorization.

21549772093 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 952560, while the sum is 49.

The spelling of 21549772093 in words is "twenty-one billion, five hundred forty-nine million, seven hundred seventy-two thousand, ninety-three".