81289029 has 4 divisors (see below), whose sum is σ = 108385376. Its totient is φ = 54192684.

The previous prime is 81289003. The next prime is 81289063. The reversal of 81289029 is 92098218.

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 not a de Polignac number, because 81289029 - 2⁵ = 81288997 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 (81289729) 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, 13548169 + ... + 13548174.

It is an arithmetic number, because the mean of its divisors is an integer number (27096344).

Almost surely, 2^81289029 is an apocalyptic number.

It is an amenable number.

81289029 is a deficient number, since it is larger than the sum of its proper divisors (27096347).

81289029 is a wasteful number, since it uses less digits than its factorization.

81289029 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27096346.

The product of its (nonzero) digits is 20736, while the sum is 39.

The square root of 81289029 is about 9016.0428681323. The cubic root of 81289029 is about 433.1888922276.

The spelling of 81289029 in words is "eighty-one million, two hundred eighty-nine thousand, twenty-nine".