81481629 has 8 divisors (see below), whose sum is σ = 115032960. Its totient is φ = 51125696.

The previous prime is 81481601. The next prime is 81481639. The reversal of 81481629 is 92618418.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 81481629 - 2⁷ = 81481501 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81481639) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 798789 + ... + 798890.

It is an arithmetic number, because the mean of its divisors is an integer number (14379120).

Almost surely, 2^81481629 is an apocalyptic number.

It is an amenable number.

81481629 is a deficient number, since it is larger than the sum of its proper divisors (33551331).

81481629 is a wasteful number, since it uses less digits than its factorization.

81481629 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1597699.

The product of its digits is 27648, while the sum is 39.

The square root of 81481629 is about 9026.7175097042. The cubic root of 81481629 is about 433.5307439127.

The spelling of 81481629 in words is "eighty-one million, four hundred eighty-one thousand, six hundred twenty-nine".