81209106 has 48 divisors (see below), whose sum is σ = 198581760. Its totient is φ = 23758560.

The previous prime is 81209101. The next prime is 81209111. The reversal of 81209106 is 60190218.

It is an interprime number because it is at equal distance from previous prime (81209101) and next prime (81209111).

It is a self number, because there is not a number n which added to its sum of digits gives 81209106.

It is not an unprimeable number, because it can be changed into a prime (81209101) 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 23 ways as a sum of consecutive naturals, for example, 1330 + ... + 12813.

It is an arithmetic number, because the mean of its divisors is an integer number (4137120).

Almost surely, 2^81209106 is an apocalyptic number.

81209106 is an abundant number, since it is smaller than the sum of its proper divisors (117372654).

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

81209106 is a wasteful number, since it uses less digits than its factorization.

81209106 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14191 (or 14188 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 27.

The square root of 81209106 is about 9011.6095121793. The cubic root of 81209106 is about 433.0468758977.

The spelling of 81209106 in words is "eighty-one million, two hundred nine thousand, one hundred six".