81429551 has 8 divisors (see below), whose sum is σ = 93144480. Its totient is φ = 69735168.

The previous prime is 81429527. The next prime is 81429559. The reversal of 81429551 is 15592418.

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 81429551 - 2¹⁸ = 81167407 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 (81429559) 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 7 ways as a sum of consecutive naturals, for example, 4595 + ... + 13563.

It is an arithmetic number, because the mean of its divisors is an integer number (11643060).

Almost surely, 2^81429551 is an apocalyptic number.

81429551 is a deficient number, since it is larger than the sum of its proper divisors (11714929).

81429551 is a wasteful number, since it uses less digits than its factorization.

81429551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10273.

The product of its digits is 14400, while the sum is 35.

The square root of 81429551 is about 9023.8323898441. The cubic root of 81429551 is about 433.4383622471.

The spelling of 81429551 in words is "eighty-one million, four hundred twenty-nine thousand, five hundred fifty-one".