9981288649 has 2 divisors, whose sum is σ = 9981288650. Its totient is φ = 9981288648.

The previous prime is 9981288637. The next prime is 9981288671. The reversal of 9981288649 is 9468821899.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 7842873600 + 2138415049 = 88560^2 + 46243^2 .

It is an emirp because it is prime and its reverse (9468821899) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 9981288649 - 2¹⁹ = 9980764361 is a prime.

It is a super-2 number, since 2×9981288649² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (9981288689) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4990644324 + 4990644325.

It is an arithmetic number, because the mean of its divisors is an integer number (4990644325).

Almost surely, 2^9981288649 is an apocalyptic number.

It is an amenable number.

9981288649 is a deficient number, since it is larger than the sum of its proper divisors (1).

9981288649 is an equidigital number, since it uses as much as digits as its factorization.

9981288649 is an evil number, because the sum of its binary digits is even.

The product of its digits is 17915904, while the sum is 64.

The square root of 9981288649 is about 99906.3994396755. The cubic root of 9981288649 is about 2153.0901049263.

The spelling of 9981288649 in words is "nine billion, nine hundred eighty-one million, two hundred eighty-eight thousand, six hundred forty-nine".