81930394 has 96 divisors (see below), whose sum is σ = 168981120. Its totient is φ = 28957824.

The previous prime is 81930391. The next prime is 81930397. The reversal of 81930394 is 49303918.

It is an interprime number because it is at equal distance from previous prime (81930391) and next prime (81930397).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81930391) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1905337 + ... + 1905379.

It is an arithmetic number, because the mean of its divisors is an integer number (1760220).

Almost surely, 2^81930394 is an apocalyptic number.

81930394 is an abundant number, since it is smaller than the sum of its proper divisors (87050726).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81930394 is a wasteful number, since it uses less digits than its factorization.

81930394 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 132 (or 113 counting only the distinct ones).

The product of its (nonzero) digits is 23328, while the sum is 37.

The square root of 81930394 is about 9051.5409737790. The cubic root of 81930394 is about 434.3251861445.

It can be divided in two parts, 819 and 30394, that added together give a palindrome (31213).

The spelling of 81930394 in words is "eighty-one million, nine hundred thirty thousand, three hundred ninety-four".