81031718 has 8 divisors (see below), whose sum is σ = 122422440. Its totient is φ = 40224240.

The previous prime is 81031711. The next prime is 81031723. The reversal of 81031718 is 81713018.

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

It is a super-2 number, since 2×81031718² = 13132278644063048, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81031711) 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, 145463 + ... + 146018.

It is an arithmetic number, because the mean of its divisors is an integer number (15302805).

Almost surely, 2^81031718 is an apocalyptic number.

81031718 is a deficient number, since it is larger than the sum of its proper divisors (41390722).

81031718 is a wasteful number, since it uses less digits than its factorization.

81031718 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 291622.

The product of its (nonzero) digits is 1344, while the sum is 29.

The square root of 81031718 is about 9001.7619386429. The cubic root of 81031718 is about 432.7313393665.

The spelling of 81031718 in words is "eighty-one million, thirty-one thousand, seven hundred eighteen".