9921549893 has 2 divisors, whose sum is σ = 9921549894. Its totient is φ = 9921549892.

The previous prime is 9921549871. The next prime is 9921549947. The reversal of 9921549893 is 3989451299.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 9912591844 + 8958049 = 99562^2 + 2993^2 .

It is a cyclic number.

It is not a de Polignac number, because 9921549893 - 2⁶ = 9921549829 is a prime.

It is a super-2 number, since 2×9921549893² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (9921549823) 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, 4960774946 + 4960774947.

It is an arithmetic number, because the mean of its divisors is an integer number (4960774947).

Almost surely, 2^9921549893 is an apocalyptic number.

It is an amenable number.

9921549893 is a deficient number, since it is larger than the sum of its proper divisors (1).

9921549893 is an equidigital number, since it uses as much as digits as its factorization.

9921549893 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6298560, while the sum is 59.

The square root of 9921549893 is about 99606.9771301188. The cubic root of 9921549893 is about 2148.7860385367.

The spelling of 9921549893 in words is "nine billion, nine hundred twenty-one million, five hundred forty-nine thousand, eight hundred ninety-three".