81002200072 has 32 divisors (see below), whose sum is σ = 159938049600. Its totient is φ = 38353794624.

The previous prime is 81002200057. The next prime is 81002200079. The reversal of 81002200072 is 27000220018.

It is a super-2 number, since 2×81002200072² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (81002200079) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 268933 + ... + 484075.

It is an arithmetic number, because the mean of its divisors is an integer number (4998064050).

Almost surely, 2^81002200072 is an apocalyptic number.

It is an amenable number.

81002200072 is a deficient number, since it is larger than the sum of its proper divisors (78935849528).

81002200072 is a wasteful number, since it uses less digits than its factorization.

81002200072 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 217645 (or 217641 counting only the distinct ones).

The product of its (nonzero) digits is 448, while the sum is 22.

The spelling of 81002200072 in words is "eighty-one billion, two million, two hundred thousand, seventy-two".