81130923 has 32 divisors (see below), whose sum is σ = 124750080. Its totient is φ = 52073280.

The previous prime is 81130921. The next prime is 81130939. The reversal of 81130923 is 32903118.

It is not a de Polignac number, because 81130923 - 2¹ = 81130921 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (81130921) 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 31 ways as a sum of consecutive naturals, for example, 91440 + ... + 92322.

It is an arithmetic number, because the mean of its divisors is an integer number (3898440).

Almost surely, 2^81130923 is an apocalyptic number.

81130923 is a gapful number since it is divisible by the number (83) formed by its first and last digit.

81130923 is a deficient number, since it is larger than the sum of its proper divisors (43619157).

81130923 is a wasteful number, since it uses less digits than its factorization.

81130923 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1016 (or 1010 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 27.

The square root of 81130923 is about 9007.2705632728. The cubic root of 81130923 is about 432.9078612129.

The spelling of 81130923 in words is "eighty-one million, one hundred thirty thousand, nine hundred twenty-three".