991127055 has 16 divisors (see below), whose sum is σ = 1640486880. Its totient is φ = 510373248.

The previous prime is 991126973. The next prime is 991127099. The reversal of 991127055 is 550721199.

It is not a de Polignac number, because 991127055 - 2¹⁷ = 990995983 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1138792 + ... + 1139661.

It is an arithmetic number, because the mean of its divisors is an integer number (102530430).

Almost surely, 2^991127055 is an apocalyptic number.

991127055 is a deficient number, since it is larger than the sum of its proper divisors (649359825).

991127055 is a wasteful number, since it uses less digits than its factorization.

991127055 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2278490.

The product of its (nonzero) digits is 28350, while the sum is 39.

The square root of 991127055 is about 31482.1704302610. The cubic root of 991127055 is about 997.0335606053.

The spelling of 991127055 in words is "nine hundred ninety-one million, one hundred twenty-seven thousand, fifty-five".