81302187 has 8 divisors (see below), whose sum is σ = 108583936. Its totient is φ = 54110952.

The previous prime is 81302183. The next prime is 81302189. The reversal of 81302187 is 78120318.

It is a happy number.

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

It is not a de Polignac number, because 81302187 - 2² = 81302183 is a prime.

It is a super-2 number, since 2×81302187² = 13220091221965938, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81302183) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 20503 + ... + 24144.

It is an arithmetic number, because the mean of its divisors is an integer number (13572992).

Almost surely, 2^81302187 is an apocalyptic number.

81302187 is a deficient number, since it is larger than the sum of its proper divisors (27281749).

81302187 is a wasteful number, since it uses less digits than its factorization.

81302187 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45257.

The product of its (nonzero) digits is 2688, while the sum is 30.

The square root of 81302187 is about 9016.7725378874. The cubic root of 81302187 is about 433.2122639421.

The spelling of 81302187 in words is "eighty-one million, three hundred two thousand, one hundred eighty-seven".