81613658 has 16 divisors (see below), whose sum is σ = 140253120. Its totient is φ = 34891296.

The previous prime is 81613639. The next prime is 81613673. The reversal of 81613658 is 85631618.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1091 + ... + 12822.

It is an arithmetic number, because the mean of its divisors is an integer number (8765820).

Almost surely, 2^81613658 is an apocalyptic number.

81613658 is a deficient number, since it is larger than the sum of its proper divisors (58639462).

81613658 is a wasteful number, since it uses less digits than its factorization.

81613658 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14341.

The product of its digits is 34560, while the sum is 38.

The square root of 81613658 is about 9034.0277838847. The cubic root of 81613658 is about 433.7647751641.

The spelling of 81613658 in words is "eighty-one million, six hundred thirteen thousand, six hundred fifty-eight".