81158650 has 12 divisors (see below), whose sum is σ = 150955182. Its totient is φ = 32463440.

The previous prime is 81158647. The next prime is 81158653. The reversal of 81158650 is 5685118.

It is an interprime number because it is at equal distance from previous prime (81158647) and next prime (81158653).

It can be written as a sum of positive squares in 3 ways, for example, as 56685841 + 24472809 = 7529^2 + 4947^2 .

It is not an unprimeable number, because it can be changed into a prime (81158653) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 811537 + ... + 811636.

Almost surely, 2^81158650 is an apocalyptic number.

81158650 is a deficient number, since it is larger than the sum of its proper divisors (69796532).

81158650 is a wasteful number, since it uses less digits than its factorization.

81158650 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1623185 (or 1623180 counting only the distinct ones).

The product of its (nonzero) digits is 9600, while the sum is 34.

The square root of 81158650 is about 9008.8095772971. The cubic root of 81158650 is about 432.9571719183.

The spelling of 81158650 in words is "eighty-one million, one hundred fifty-eight thousand, six hundred fifty".