81618326 has 16 divisors (see below), whose sum is σ = 130507200. Its totient is φ = 38148480.

The previous prime is 81618323. The next prime is 81618347. The reversal of 81618326 is 62381618.

It is a super-2 number, since 2×81618326² = 13323102278084552, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81618323) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2990 + ... + 13121.

It is an arithmetic number, because the mean of its divisors is an integer number (8156700).

Almost surely, 2^81618326 is an apocalyptic number.

81618326 is a deficient number, since it is larger than the sum of its proper divisors (48888874).

81618326 is a wasteful number, since it uses less digits than its factorization.

81618326 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16279.

The product of its digits is 13824, while the sum is 35.

The square root of 81618326 is about 9034.2861367127. The cubic root of 81618326 is about 433.7730449211.

The spelling of 81618326 in words is "eighty-one million, six hundred eighteen thousand, three hundred twenty-six".