9981555 has 16 divisors (see below), whose sum is σ = 16811520. Its totient is φ = 5043168.

The previous prime is 9981551. The next prime is 9981557. The reversal of 9981555 is 5551899.

It is a happy number.

9981555 is digitally balanced in base 2 and base 4, because in such bases it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 9981555 - 2² = 9981551 is a prime.

It is not an unprimeable number, because it can be changed into a prime (9981551) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 17227 + ... + 17796.

It is an arithmetic number, because the mean of its divisors is an integer number (1050720).

Almost surely, 2^9981555 is an apocalyptic number.

9981555 is a gapful number since it is divisible by the number (95) formed by its first and last digit.

9981555 is a deficient number, since it is larger than the sum of its proper divisors (6829965).

9981555 is a wasteful number, since it uses less digits than its factorization.

9981555 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35050.

The product of its digits is 81000, while the sum is 42.

The square root of 9981555 is about 3159.3599035248. The cubic root of 9981555 is about 215.3109256515.

The spelling of 9981555 in words is "nine million, nine hundred eighty-one thousand, five hundred fifty-five".