81429291 has 12 divisors (see below), whose sum is σ = 117713232. Its totient is φ = 54243216.

The previous prime is 81429289. The next prime is 81429323. The reversal of 81429291 is 19292418.

It is not a de Polignac number, because 81429291 - 2¹ = 81429289 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81429211) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 11970 + ... + 17496.

It is an arithmetic number, because the mean of its divisors is an integer number (9809436).

Almost surely, 2^81429291 is an apocalyptic number.

81429291 is a deficient number, since it is larger than the sum of its proper divisors (36283941).

81429291 is a wasteful number, since it uses less digits than its factorization.

81429291 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7170 (or 7167 counting only the distinct ones).

The product of its digits is 10368, while the sum is 36.

The square root of 81429291 is about 9023.8179835367. The cubic root of 81429291 is about 433.4379009318.

The spelling of 81429291 in words is "eighty-one million, four hundred twenty-nine thousand, two hundred ninety-one".