81609367558 has 8 divisors (see below), whose sum is σ = 122448227328. Its totient is φ = 40793291784.

The previous prime is 81609367547. The next prime is 81609367597. The reversal of 81609367558 is 85576390618.

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

It is a congruent number.

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, 5687041 + ... + 5701372.

It is an arithmetic number, because the mean of its divisors is an integer number (15306028416).

Almost surely, 2^81609367558 is an apocalyptic number.

81609367558 is a deficient number, since it is larger than the sum of its proper divisors (40838859770).

81609367558 is a wasteful number, since it uses less digits than its factorization.

81609367558 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11391998.

The product of its (nonzero) digits is 10886400, while the sum is 58.

The spelling of 81609367558 in words is "eighty-one billion, six hundred nine million, three hundred sixty-seven thousand, five hundred fifty-eight".