81531102 has 8 divisors (see below), whose sum is σ = 163062216. Its totient is φ = 27177032.

The previous prime is 81531101. The next prime is 81531143. The reversal of 81531102 is 20113518.

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

81531102 is an admirable number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81531101) 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 3 ways as a sum of consecutive naturals, for example, 6794253 + ... + 6794264.

It is an arithmetic number, because the mean of its divisors is an integer number (20382777).

Almost surely, 2^81531102 is an apocalyptic number.

81531102 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81531102 is a wasteful number, since it uses less digits than its factorization.

81531102 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13588522.

The product of its (nonzero) digits is 240, while the sum is 21.

The square root of 81531102 is about 9029.4574587846. The cubic root of 81531102 is about 433.6184680920.

The spelling of 81531102 in words is "eighty-one million, five hundred thirty-one thousand, one hundred two".