81303568 has 20 divisors (see below), whose sum is σ = 157682988. Its totient is φ = 40611200.

The previous prime is 81303553. The next prime is 81303569. The reversal of 81303568 is 86530318.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 62916624 + 18386944 = 7932^2 + 4288^2 .

It is a super-2 number, since 2×81303568² = 13220540339061248, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (81303569) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 20118 + ... + 23818.

Almost surely, 2^81303568 is an apocalyptic number.

It is an amenable number.

81303568 is a deficient number, since it is larger than the sum of its proper divisors (76379420).

81303568 is a wasteful number, since it uses less digits than its factorization.

81303568 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5082 (or 5076 counting only the distinct ones).

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

The square root of 81303568 is about 9016.8491170697. The cubic root of 81303568 is about 433.2147167779.

The spelling of 81303568 in words is "eighty-one million, three hundred three thousand, five hundred sixty-eight".