99971823 has 32 divisors (see below), whose sum is σ = 159768576. Its totient is φ = 54366048.

The previous prime is 99971813. The next prime is 99971827. The reversal of 99971823 is 32817999.

It is not a de Polignac number, because 99971823 - 2⁶ = 99971759 is a prime.

It is a Smith number, since the sum of its digits (48) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (99971827) 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 31 ways as a sum of consecutive naturals, for example, 126636 + ... + 127422.

It is an arithmetic number, because the mean of its divisors is an integer number (4992768).

Almost surely, 2^99971823 is an apocalyptic number.

99971823 is a deficient number, since it is larger than the sum of its proper divisors (59796753).

99971823 is a wasteful number, since it uses less digits than its factorization.

99971823 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1083.

The product of its digits is 244944, while the sum is 48.

The square root of 99971823 is about 9998.5910507431. The cubic root of 99971823 is about 464.1152839165.

The spelling of 99971823 in words is "ninety-nine million, nine hundred seventy-one thousand, eight hundred twenty-three".