81929229 has 16 divisors (see below), whose sum is σ = 111451200. Its totient is φ = 53519616.

The previous prime is 81929227. The next prime is 81929231. The reversal of 81929229 is 92292918.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (81929227) and next prime (81929231).

It is not a de Polignac number, because 81929229 - 2¹ = 81929227 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81929227) 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, 76107 + ... + 77175.

It is an arithmetic number, because the mean of its divisors is an integer number (6965700).

Almost surely, 2^81929229 is an apocalyptic number.

It is an amenable number.

81929229 is a deficient number, since it is larger than the sum of its proper divisors (29521971).

81929229 is a wasteful number, since it uses less digits than its factorization.

81929229 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1564.

The product of its digits is 46656, while the sum is 42.

The square root of 81929229 is about 9051.4766198671. The cubic root of 81929229 is about 434.3231275220.

The spelling of 81929229 in words is "eighty-one million, nine hundred twenty-nine thousand, two hundred twenty-nine".