81091336966 has 4 divisors (see below), whose sum is σ = 121637005452. Its totient is φ = 40545668482.

The previous prime is 81091336961. The next prime is 81091336981. The reversal of 81091336966 is 66963319018.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81091336961) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20272834240 + ... + 20272834243.

It is an arithmetic number, because the mean of its divisors is an integer number (30409251363).

Almost surely, 2^81091336966 is an apocalyptic number.

81091336966 is a deficient number, since it is larger than the sum of its proper divisors (40545668486).

81091336966 is a wasteful number, since it uses less digits than its factorization.

81091336966 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40545668485.

The product of its (nonzero) digits is 1259712, while the sum is 52.

The spelling of 81091336966 in words is "eighty-one billion, ninety-one million, three hundred thirty-six thousand, nine hundred sixty-six".