81713378 has 8 divisors (see below), whose sum is σ = 122624172. Its totient is φ = 40838656.

The previous prime is 81713377. The next prime is 81713381. The reversal of 81713378 is 87331718.

It can be written as a sum of positive squares in 2 ways, for example, as 65496649 + 16216729 = 8093^2 + 4027^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×81713378² = 13354152288341768, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (81713377) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2375 + ... + 13002.

Almost surely, 2^81713378 is an apocalyptic number.

81713378 is a deficient number, since it is larger than the sum of its proper divisors (40910794).

81713378 is a wasteful number, since it uses less digits than its factorization.

81713378 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18036.

The product of its digits is 28224, while the sum is 38.

The square root of 81713378 is about 9039.5452319240. The cubic root of 81713378 is about 433.9413690467.

The spelling of 81713378 in words is "eighty-one million, seven hundred thirteen thousand, three hundred seventy-eight".