991922811 has 8 divisors (see below), whose sum is σ = 1442796864. Its totient is φ = 601165320.

The previous prime is 991922807. The next prime is 991922831. The reversal of 991922811 is 118229199.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 991922811 - 2² = 991922807 is a prime.

It is not an unprimeable number, because it can be changed into a prime (991922831) 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 in 7 ways as a sum of consecutive naturals, for example, 15029101 + ... + 15029166.

It is an arithmetic number, because the mean of its divisors is an integer number (180349608).

Almost surely, 2^991922811 is an apocalyptic number.

991922811 is a deficient number, since it is larger than the sum of its proper divisors (450874053).

991922811 is a wasteful number, since it uses less digits than its factorization.

991922811 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30058281.

The product of its digits is 23328, while the sum is 42.

The square root of 991922811 is about 31494.8060956088. The cubic root of 991922811 is about 997.3003219638.

The spelling of 991922811 in words is "nine hundred ninety-one million, nine hundred twenty-two thousand, eight hundred eleven".