81823438 has 8 divisors (see below), whose sum is σ = 122787432. Its totient is φ = 40894296.

The previous prime is 81823411. The next prime is 81823459. The reversal of 81823438 is 83432818.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×81823438² = 13390150012279688, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 81823397 and 81823406.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1720 + ... + 12907.

It is an arithmetic number, because the mean of its divisors is an integer number (15348429).

Almost surely, 2^81823438 is an apocalyptic number.

81823438 is a deficient number, since it is larger than the sum of its proper divisors (40963994).

81823438 is a wasteful number, since it uses less digits than its factorization.

81823438 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17426.

The product of its digits is 36864, while the sum is 37.

The square root of 81823438 is about 9045.6308790487. The cubic root of 81823438 is about 434.1361072962.

The spelling of 81823438 in words is "eighty-one million, eight hundred twenty-three thousand, four hundred thirty-eight".