81013384 has 8 divisors (see below), whose sum is σ = 151900110. Its totient is φ = 40506688.

The previous prime is 81013369. The next prime is 81013391. The reversal of 81013384 is 48331018.

It can be written as a sum of positive squares in only one way, i.e., 77053284 + 3960100 = 8778^2 + 1990^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is a hoax number, since the sum of its digits (28) coincides with the sum of the digits of its distinct prime factors.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5063329 + ... + 5063344.

Almost surely, 2^81013384 is an apocalyptic number.

It is an amenable number.

81013384 is a deficient number, since it is larger than the sum of its proper divisors (70886726).

81013384 is a wasteful number, since it uses less digits than its factorization.

81013384 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10126679 (or 10126675 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 28.

The square root of 81013384 is about 9000.7435248428. The cubic root of 81013384 is about 432.6987007282.

The spelling of 81013384 in words is "eighty-one million, thirteen thousand, three hundred eighty-four".