81903873 has 4 divisors (see below), whose sum is σ = 109205168. Its totient is φ = 54602580.

The previous prime is 81903847. The next prime is 81903881. The reversal of 81903873 is 37830918.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 81903873 - 2¹² = 81899777 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81903893) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13650643 + ... + 13650648.

It is an arithmetic number, because the mean of its divisors is an integer number (27301292).

Almost surely, 2^81903873 is an apocalyptic number.

It is an amenable number.

81903873 is a deficient number, since it is larger than the sum of its proper divisors (27301295).

81903873 is a wasteful number, since it uses less digits than its factorization.

81903873 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27301294.

The product of its (nonzero) digits is 36288, while the sum is 39.

The square root of 81903873 is about 9050.0758560357. The cubic root of 81903873 is about 434.2783171670.

The spelling of 81903873 in words is "eighty-one million, nine hundred three thousand, eight hundred seventy-three".