81646165022 has 4 divisors (see below), whose sum is σ = 122469247536. Its totient is φ = 40823082510.

The previous prime is 81646165021. The next prime is 81646165031. The reversal of 81646165022 is 22056164618.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 22056164618 = 2 ⋅11028082309.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81646165021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20411541254 + ... + 20411541257.

It is an arithmetic number, because the mean of its divisors is an integer number (30617311884).

Almost surely, 2^81646165022 is an apocalyptic number.

81646165022 is a deficient number, since it is larger than the sum of its proper divisors (40823082514).

81646165022 is a wasteful number, since it uses less digits than its factorization.

81646165022 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40823082513.

The product of its (nonzero) digits is 138240, while the sum is 41.

The spelling of 81646165022 in words is "eighty-one billion, six hundred forty-six million, one hundred sixty-five thousand, twenty-two".