81219325364 has 6 divisors (see below), whose sum is σ = 142133819394. Its totient is φ = 40609662680.

The previous prime is 81219325351. The next prime is 81219325399. The reversal of 81219325364 is 46352391218.

It can be written as a sum of positive squares in only one way, i.e., 79107187600 + 2112137764 = 281260^2 + 45958^2 .

It is a congruent number.

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 10152415667 + ... + 10152415674.

It is an arithmetic number, because the mean of its divisors is an integer number (23688969899).

Almost surely, 2^81219325364 is an apocalyptic number.

It is an amenable number.

81219325364 is a deficient number, since it is larger than the sum of its proper divisors (60914494030).

81219325364 is a wasteful number, since it uses less digits than its factorization.

81219325364 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20304831345 (or 20304831343 counting only the distinct ones).

The product of its digits is 311040, while the sum is 44.

The spelling of 81219325364 in words is "eighty-one billion, two hundred nineteen million, three hundred twenty-five thousand, three hundred sixty-four".