81529516 has 6 divisors (see below), whose sum is σ = 142676660. Its totient is φ = 40764756.

The previous prime is 81529507. The next prime is 81529517. The reversal of 81529516 is 61592518.

It is not an unprimeable number, because it can be changed into a prime (81529517) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10191186 + ... + 10191193.

Almost surely, 2^81529516 is an apocalyptic number.

It is an amenable number.

81529516 is a deficient number, since it is larger than the sum of its proper divisors (61147144).

81529516 is a wasteful number, since it uses less digits than its factorization.

81529516 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20382383 (or 20382381 counting only the distinct ones).

The product of its digits is 21600, while the sum is 37.

The square root of 81529516 is about 9029.3696346977. The cubic root of 81529516 is about 433.6156563906.

The spelling of 81529516 in words is "eighty-one million, five hundred twenty-nine thousand, five hundred sixteen".