81209110 has 24 divisors (see below), whose sum is σ = 149859648. Its totient is φ = 31684800.

The previous prime is 81209101. The next prime is 81209111. The reversal of 81209110 is 1190218.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81209111) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 14395 + ... + 19225.

It is an arithmetic number, because the mean of its divisors is an integer number (6244152).

Almost surely, 2^81209110 is an apocalyptic number.

81209110 is a deficient number, since it is larger than the sum of its proper divisors (68650538).

81209110 is a wasteful number, since it uses less digits than its factorization.

81209110 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4920 (or 4879 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 22.

The square root of 81209110 is about 9011.6097341152. The cubic root of 81209110 is about 433.0468830077.

Adding to 81209110 its reverse (1190218), we get a palindrome (82399328).

The spelling of 81209110 in words is "eighty-one million, two hundred nine thousand, one hundred ten".