991032823 has 16 divisors (see below), whose sum is σ = 1098748800. Its totient is φ = 886372000.

The previous prime is 991032821. The next prime is 991032829. The reversal of 991032823 is 328230199.

It is a cyclic number.

It is not a de Polignac number, because 991032823 - 2¹ = 991032821 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (991032821) 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, 172548 + ... + 178198.

It is an arithmetic number, because the mean of its divisors is an integer number (68671800).

Almost surely, 2^991032823 is an apocalyptic number.

991032823 is a deficient number, since it is larger than the sum of its proper divisors (107715977).

991032823 is a wasteful number, since it uses less digits than its factorization.

991032823 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5918.

The product of its (nonzero) digits is 23328, while the sum is 37.

The square root of 991032823 is about 31480.6738015564. The cubic root of 991032823 is about 997.0019617490.

It can be divided in two parts, 99103 and 2823, that added together give a triangular number (101926 = T₄₅₁).

The spelling of 991032823 in words is "nine hundred ninety-one million, thirty-two thousand, eight hundred twenty-three".