81204635 has 4 divisors (see below), whose sum is σ = 97445568. Its totient is φ = 64963704.

The previous prime is 81204589. The next prime is 81204649. The reversal of 81204635 is 53640218.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 81204635 - 2²² = 77010331 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 81204598 and 81204607.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8120459 + ... + 8120468.

It is an arithmetic number, because the mean of its divisors is an integer number (24361392).

Almost surely, 2^81204635 is an apocalyptic number.

81204635 is a deficient number, since it is larger than the sum of its proper divisors (16240933).

81204635 is a wasteful number, since it uses less digits than its factorization.

81204635 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16240932.

The product of its (nonzero) digits is 5760, while the sum is 29.

The square root of 81204635 is about 9011.3614398713. The cubic root of 81204635 is about 433.0389285618.

The spelling of 81204635 in words is "eighty-one million, two hundred four thousand, six hundred thirty-five".