81407829 has 16 divisors (see below), whose sum is σ = 112656384. Its totient is φ = 52234800.

The previous prime is 81407803. The next prime is 81407839. The reversal of 81407829 is 92870418.

It is not a de Polignac number, because 81407829 - 2⁹ = 81407317 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81407839) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 15472 + ... + 20054.

It is an arithmetic number, because the mean of its divisors is an integer number (7041024).

Almost surely, 2^81407829 is an apocalyptic number.

It is an amenable number.

81407829 is a deficient number, since it is larger than the sum of its proper divisors (31248555).

81407829 is a wasteful number, since it uses less digits than its factorization.

81407829 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4808.

The product of its (nonzero) digits is 32256, while the sum is 39.

The square root of 81407829 is about 9022.6287189488. The cubic root of 81407829 is about 433.3998177412.

The spelling of 81407829 in words is "eighty-one million, four hundred seven thousand, eight hundred twenty-nine".