81764884 has 12 divisors (see below), whose sum is σ = 143281908. Its totient is φ = 40827200.

The previous prime is 81764869. The next prime is 81764899. The reversal of 81764884 is 48846718.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (81764869) and next prime (81764899).

It can be written as a sum of positive squares in 2 ways, for example, as 944784 + 80820100 = 972^2 + 8990^2 .

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 in 3 ways as a sum of consecutive naturals, for example, 10387 + ... + 16474.

It is an arithmetic number, because the mean of its divisors is an integer number (11940159).

Almost surely, 2^81764884 is an apocalyptic number.

It is an amenable number.

81764884 is a deficient number, since it is larger than the sum of its proper divisors (61517024).

81764884 is a wasteful number, since it uses less digits than its factorization.

81764884 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27626 (or 27624 counting only the distinct ones).

The product of its digits is 344064, while the sum is 46.

The square root of 81764884 is about 9042.3937096324. The cubic root of 81764884 is about 434.0325246212.

The spelling of 81764884 in words is "eighty-one million, seven hundred sixty-four thousand, eight hundred eighty-four".