81563607 has 6 divisors (see below), whose sum is σ = 117814112. Its totient is φ = 54375732.

The previous prime is 81563579. The next prime is 81563609. The reversal of 81563607 is 70636518.

81563607 is a `hidden beast` number, since 8 + 15 + 636 + 0 + 7 = 666.

It is not a de Polignac number, because 81563607 - 2⁷ = 81563479 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 (81563609) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 4531303 + ... + 4531320.

Almost surely, 2^81563607 is an apocalyptic number.

81563607 is a deficient number, since it is larger than the sum of its proper divisors (36250505).

81563607 is a wasteful number, since it uses less digits than its factorization.

81563607 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9062629 (or 9062626 counting only the distinct ones).

The product of its (nonzero) digits is 30240, while the sum is 36.

The square root of 81563607 is about 9031.2572214504. The cubic root of 81563607 is about 433.6760857588.

The spelling of 81563607 in words is "eighty-one million, five hundred sixty-three thousand, six hundred seven".