81225829 has 4 divisors (see below), whose sum is σ = 81414720. Its totient is φ = 81036940.

The previous prime is 81225791. The next prime is 81225853. The reversal of 81225829 is 92852218.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 81225829 - 2⁷ = 81225701 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81225899) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 93799 + ... + 94660.

It is an arithmetic number, because the mean of its divisors is an integer number (20353680).

Almost surely, 2^81225829 is an apocalyptic number.

It is an amenable number.

81225829 is a deficient number, since it is larger than the sum of its proper divisors (188891).

81225829 is a wasteful number, since it uses less digits than its factorization.

81225829 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 188890.

The product of its digits is 23040, while the sum is 37.

The square root of 81225829 is about 9012.5373230850. The cubic root of 81225829 is about 433.0765989432.

The spelling of 81225829 in words is "eighty-one million, two hundred twenty-five thousand, eight hundred twenty-nine".