81529057 has 8 divisors (see below), whose sum is σ = 86609600. Its totient is φ = 76527504.

The previous prime is 81529051. The next prime is 81529061. The reversal of 81529057 is 75092518.

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

It is a 7-Lehmer number, since φ(81529057) divides (81529057-1)⁷.

It is a cyclic number.

It is not a de Polignac number, because 81529057 - 2¹⁹ = 81004769 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81529051) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 17613 + ... + 21754.

It is an arithmetic number, because the mean of its divisors is an integer number (10826200).

Almost surely, 2^81529057 is an apocalyptic number.

It is an amenable number.

81529057 is a deficient number, since it is larger than the sum of its proper divisors (5080543).

81529057 is a wasteful number, since it uses less digits than its factorization.

81529057 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39495.

The product of its (nonzero) digits is 25200, while the sum is 37.

The square root of 81529057 is about 9029.3442176052. The cubic root of 81529057 is about 433.6148426568.

The spelling of 81529057 in words is "eighty-one million, five hundred twenty-nine thousand, fifty-seven".