81335764 has 6 divisors (see below), whose sum is σ = 142337594. Its totient is φ = 40667880.

The previous prime is 81335743. The next prime is 81335773. The reversal of 81335764 is 46753318.

It can be written as a sum of positive squares in only one way, i.e., 79210000 + 2125764 = 8900^2 + 1458^2 .

It is a congruent number.

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 10166967 + ... + 10166974.

Almost surely, 2^81335764 is an apocalyptic number.

It is an amenable number.

81335764 is a deficient number, since it is larger than the sum of its proper divisors (61001830).

81335764 is a wasteful number, since it uses less digits than its factorization.

81335764 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20333945 (or 20333943 counting only the distinct ones).

The product of its digits is 60480, while the sum is 37.

The square root of 81335764 is about 9018.6342646767. The cubic root of 81335764 is about 433.2718931958.

The spelling of 81335764 in words is "eighty-one million, three hundred thirty-five thousand, seven hundred sixty-four".