81563308 has 6 divisors (see below), whose sum is σ = 142735796. Its totient is φ = 40781652.

The previous prime is 81563299. The next prime is 81563329. The reversal of 81563308 is 80336518.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10195410 + ... + 10195417.

Almost surely, 2^81563308 is an apocalyptic number.

It is an amenable number.

81563308 is a deficient number, since it is larger than the sum of its proper divisors (61172488).

81563308 is a wasteful number, since it uses less digits than its factorization.

81563308 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20390831 (or 20390829 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 34.

The square root of 81563308 is about 9031.2406678152. The cubic root of 81563308 is about 433.6755558276.

The spelling of 81563308 in words is "eighty-one million, five hundred sixty-three thousand, three hundred eight".