81533763 has 8 divisors (see below), whose sum is σ = 120790800. Its totient is φ = 54355824.

The previous prime is 81533747. The next prime is 81533791. The reversal of 81533763 is 36733518.

It is not a de Polignac number, because 81533763 - 2⁴ = 81533747 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81533743) 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 7 ways as a sum of consecutive naturals, for example, 1509858 + ... + 1509911.

It is an arithmetic number, because the mean of its divisors is an integer number (15098850).

Almost surely, 2^81533763 is an apocalyptic number.

81533763 is a deficient number, since it is larger than the sum of its proper divisors (39257037).

81533763 is a wasteful number, since it uses less digits than its factorization.

81533763 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3019778 (or 3019772 counting only the distinct ones).

The product of its digits is 45360, while the sum is 36.

The square root of 81533763 is about 9029.6048086281. The cubic root of 81533763 is about 433.6231854991.

The spelling of 81533763 in words is "eighty-one million, five hundred thirty-three thousand, seven hundred sixty-three".