81209104 has 20 divisors (see below), whose sum is σ = 157806864. Its totient is φ = 40484768.

The previous prime is 81209101. The next prime is 81209111. The reversal of 81209104 is 40190218.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (81209101) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1762 + ... + 12865.

Almost surely, 2^81209104 is an apocalyptic number.

It is an amenable number.

81209104 is a deficient number, since it is larger than the sum of its proper divisors (76597760).

81209104 is a wasteful number, since it uses less digits than its factorization.

81209104 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14982 (or 14976 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 25.

The square root of 81209104 is about 9011.6094012113. The cubic root of 81209104 is about 433.0468723427.

The spelling of 81209104 in words is "eighty-one million, two hundred nine thousand, one hundred four".