81529995 has 8 divisors (see below), whose sum is σ = 130448016. Its totient is φ = 43482656.

The previous prime is 81529993. The next prime is 81530051. The reversal of 81529995 is 59992518.

It is a happy number.

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 81529995 - 2¹ = 81529993 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81529993) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2717652 + ... + 2717681.

It is an arithmetic number, because the mean of its divisors is an integer number (16306002).

Almost surely, 2^81529995 is an apocalyptic number.

81529995 is a deficient number, since it is larger than the sum of its proper divisors (48918021).

81529995 is a wasteful number, since it uses less digits than its factorization.

81529995 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5435341.

The product of its digits is 291600, while the sum is 48.

The square root of 81529995 is about 9029.3961592124. The cubic root of 81529995 is about 433.6165055779.

The spelling of 81529995 in words is "eighty-one million, five hundred twenty-nine thousand, nine hundred ninety-five".