81948623 has 4 divisors (see below), whose sum is σ = 81971088. Its totient is φ = 81926160.

The previous prime is 81948557. The next prime is 81948631. The reversal of 81948623 is 32684918.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 81948623 - 2⁸ = 81948367 is a prime.

It is a super-2 number, since 2×81948623² = 13431153623192258, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81948023) 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 3 ways as a sum of consecutive naturals, for example, 4358 + ... + 13523.

It is an arithmetic number, because the mean of its divisors is an integer number (20492772).

Almost surely, 2^81948623 is an apocalyptic number.

81948623 is a deficient number, since it is larger than the sum of its proper divisors (22465).

81948623 is a wasteful number, since it uses less digits than its factorization.

81948623 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22464.

The product of its digits is 82944, while the sum is 41.

The square root of 81948623 is about 9052.5478733890. The cubic root of 81948623 is about 434.3573953012.

The spelling of 81948623 in words is "eighty-one million, nine hundred forty-eight thousand, six hundred twenty-three".