81300511 has 4 divisors (see below), whose sum is σ = 86082912. Its totient is φ = 76518112.

The previous prime is 81300503. The next prime is 81300517. The reversal of 81300511 is 11500318.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 81300511 - 2³ = 81300503 is a prime.

It is a super-2 number, since 2×81300511² = 13219546177722242, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81300517) 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, 2391175 + ... + 2391208.

It is an arithmetic number, because the mean of its divisors is an integer number (21520728).

Almost surely, 2^81300511 is an apocalyptic number.

81300511 is a deficient number, since it is larger than the sum of its proper divisors (4782401).

81300511 is a wasteful number, since it uses less digits than its factorization.

81300511 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4782400.

The product of its (nonzero) digits is 120, while the sum is 19.

The square root of 81300511 is about 9016.6795994978. The cubic root of 81300511 is about 433.2092871106.

Adding to 81300511 its reverse (11500318), we get a palindrome (92800829).

The spelling of 81300511 in words is "eighty-one million, three hundred thousand, five hundred eleven".