81091829 has 16 divisors (see below), whose sum is σ = 105060480. Its totient is φ = 60782400.

The previous prime is 81091811. The next prime is 81091837. The reversal of 81091829 is 92819018.

It is not a de Polignac number, because 81091829 - 2⁸ = 81091573 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 81091792 and 81091801.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81091849) 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, 21722 + ... + 25179.

It is an arithmetic number, because the mean of its divisors is an integer number (6566280).

Almost surely, 2^81091829 is an apocalyptic number.

It is an amenable number.

81091829 is a deficient number, since it is larger than the sum of its proper divisors (23968651).

81091829 is a wasteful number, since it uses less digits than its factorization.

81091829 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 46940.

The product of its (nonzero) digits is 10368, while the sum is 38.

The square root of 81091829 is about 9005.1001660170. The cubic root of 81091829 is about 432.8383159298.

The spelling of 81091829 in words is "eighty-one million, ninety-one thousand, eight hundred twenty-nine".