81303764 has 6 divisors (see below), whose sum is σ = 142281594. Its totient is φ = 40651880.

The previous prime is 81303727. The next prime is 81303767. The reversal of 81303764 is 46730318.

81303764 is nontrivially palindromic in base 16.

It can be written as a sum of positive squares in only one way, i.e., 60528400 + 20775364 = 7780^2 + 4558^2 .

It is a super-2 number, since 2×81303764² = 13220604081135392, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 81303764.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81303767) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10162967 + ... + 10162974.

It is an arithmetic number, because the mean of its divisors is an integer number (23713599).

Almost surely, 2^81303764 is an apocalyptic number.

It is an amenable number.

81303764 is a deficient number, since it is larger than the sum of its proper divisors (60977830).

81303764 is a wasteful number, since it uses less digits than its factorization.

81303764 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20325945 (or 20325943 counting only the distinct ones).

The product of its (nonzero) digits is 12096, while the sum is 32.

The square root of 81303764 is about 9016.8599856047. The cubic root of 81303764 is about 433.2150648972.

The spelling of 81303764 in words is "eighty-one million, three hundred three thousand, seven hundred sixty-four".