991226471 has 4 divisors (see below), whose sum is σ = 994034832. Its totient is φ = 988418112.

The previous prime is 991226459. The next prime is 991226507. The reversal of 991226471 is 174622199.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 991226471 - 2⁶ = 991226407 is a prime.

It is a super-3 number, since 3×991226471³ (a number of 28 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (991226671) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1403651 + ... + 1404356.

It is an arithmetic number, because the mean of its divisors is an integer number (248508708).

Almost surely, 2^991226471 is an apocalyptic number.

991226471 is a deficient number, since it is larger than the sum of its proper divisors (2808361).

991226471 is a wasteful number, since it uses less digits than its factorization.

991226471 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2808360.

The product of its digits is 54432, while the sum is 41.

The square root of 991226471 is about 31483.7493161154. The cubic root of 991226471 is about 997.0668956434.

The spelling of 991226471 in words is "nine hundred ninety-one million, two hundred twenty-six thousand, four hundred seventy-one".