81204135 has 8 divisors (see below), whose sum is σ = 129926640. Its totient is φ = 43308864.

The previous prime is 81204133. The next prime is 81204163. The reversal of 81204135 is 53140218.

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

It is not a de Polignac number, because 81204135 - 2¹ = 81204133 is a prime.

It is a super-2 number, since 2×81204135² = 13188223082196450, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81204131) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2706790 + ... + 2706819.

It is an arithmetic number, because the mean of its divisors is an integer number (16240830).

Almost surely, 2^81204135 is an apocalyptic number.

81204135 is a deficient number, since it is larger than the sum of its proper divisors (48722505).

81204135 is a wasteful number, since it uses less digits than its factorization.

81204135 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5413617.

The product of its (nonzero) digits is 960, while the sum is 24.

The square root of 81204135 is about 9011.3336970728. Note that the first 3 decimals coincide. The cubic root of 81204135 is about 433.0380397788.

The spelling of 81204135 in words is "eighty-one million, two hundred four thousand, one hundred thirty-five".