81804238 has 32 divisors (see below), whose sum is σ = 137526336. Its totient is φ = 36292608.

The previous prime is 81804223. The next prime is 81804241. The reversal of 81804238 is 83240818.

It is a Harshad number since it is a multiple of its sum of digits (34).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 56370 + ... + 57802.

It is an arithmetic number, because the mean of its divisors is an integer number (4297698).

Almost surely, 2^81804238 is an apocalyptic number.

81804238 is a deficient number, since it is larger than the sum of its proper divisors (55722098).

81804238 is a wasteful number, since it uses less digits than its factorization.

81804238 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1548.

The product of its (nonzero) digits is 12288, while the sum is 34.

The square root of 81804238 is about 9044.5695309395. The cubic root of 81804238 is about 434.1021477303.

The spelling of 81804238 in words is "eighty-one million, eight hundred four thousand, two hundred thirty-eight".