81129740206 has 8 divisors (see below), whose sum is σ = 121745471904. Its totient is φ = 40547916240.

The previous prime is 81129740189. The next prime is 81129740233. The reversal of 81129740206 is 60204792118.

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, 8470950 + ... + 8480521.

It is an arithmetic number, because the mean of its divisors is an integer number (15218183988).

Almost surely, 2^81129740206 is an apocalyptic number.

81129740206 is a deficient number, since it is larger than the sum of its proper divisors (40615731698).

81129740206 is a wasteful number, since it uses less digits than its factorization.

81129740206 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16953866.

The product of its (nonzero) digits is 48384, while the sum is 40.

The spelling of 81129740206 in words is "eighty-one billion, one hundred twenty-nine million, seven hundred forty thousand, two hundred six".