81266563698 has 16 divisors (see below), whose sum is σ = 166312968096. Its totient is φ = 26458881120.

The previous prime is 81266563687. The next prime is 81266563823. The reversal of 81266563698 is 89636566218.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 157493083 + ... + 157493598.

It is an arithmetic number, because the mean of its divisors is an integer number (10394560506).

Almost surely, 2^81266563698 is an apocalyptic number.

81266563698 is an abundant number, since it is smaller than the sum of its proper divisors (85046404398).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81266563698 is a wasteful number, since it uses less digits than its factorization.

81266563698 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 314986729.

The product of its digits is 22394880, while the sum is 60.

The spelling of 81266563698 in words is "eighty-one billion, two hundred sixty-six million, five hundred sixty-three thousand, six hundred ninety-eight".