991220103 has 6 divisors (see below), whose sum is σ = 1431762384. Its totient is φ = 660813396.

The previous prime is 991220099. The next prime is 991220143. The reversal of 991220103 is 301022199.

991220103 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 991220103 - 2² = 991220099 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (991220143) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 55067775 + ... + 55067792.

It is an arithmetic number, because the mean of its divisors is an integer number (238627064).

Almost surely, 2^991220103 is an apocalyptic number.

991220103 is a deficient number, since it is larger than the sum of its proper divisors (440542281).

991220103 is a wasteful number, since it uses less digits than its factorization.

991220103 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 110135573 (or 110135570 counting only the distinct ones).

The product of its (nonzero) digits is 972, while the sum is 27.

The square root of 991220103 is about 31483.6481844147. The cubic root of 991220103 is about 997.0647604652.

The spelling of 991220103 in words is "nine hundred ninety-one million, two hundred twenty thousand, one hundred three".