81563896 has 16 divisors (see below), whose sum is σ = 153873000. Its totient is φ = 40531104.

The previous prime is 81563879. The next prime is 81563899. The reversal of 81563896 is 69836518.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81563899) 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 3 ways as a sum of consecutive naturals, for example, 29971 + ... + 32578.

Almost surely, 2^81563896 is an apocalyptic number.

It is an amenable number.

81563896 is a deficient number, since it is larger than the sum of its proper divisors (72309104).

81563896 is a wasteful number, since it uses less digits than its factorization.

81563896 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 62718 (or 62714 counting only the distinct ones).

The product of its digits is 311040, while the sum is 46.

The square root of 81563896 is about 9031.2732214234. The cubic root of 81563896 is about 433.6765979654.

The spelling of 81563896 in words is "eighty-one million, five hundred sixty-three thousand, eight hundred ninety-six".