81863093 has 6 divisors (see below), whose sum is σ = 88644834. Its totient is φ = 75565776.

The previous prime is 81863087. The next prime is 81863107. The reversal of 81863093 is 39036818.

It can be written as a sum of positive squares in 3 ways, for example, as 14884 + 81848209 = 122^2 + 9047^2 .

It is a de Polignac number, because none of the positive numbers 2^k-81863093 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 (81863063) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 242030 + ... + 242367.

It is an arithmetic number, because the mean of its divisors is an integer number (14774139).

Almost surely, 2^81863093 is an apocalyptic number.

It is an amenable number.

81863093 is a deficient number, since it is larger than the sum of its proper divisors (6781741).

81863093 is a wasteful number, since it uses less digits than its factorization.

81863093 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 484423 (or 484410 counting only the distinct ones).

The product of its (nonzero) digits is 31104, while the sum is 38.

The square root of 81863093 is about 9047.8225557313. The cubic root of 81863093 is about 434.2062293679.

The spelling of 81863093 in words is "eighty-one million, eight hundred sixty-three thousand, ninety-three".