81219365412 has 48 divisors (see below), whose sum is σ = 194190565632. Its totient is φ = 26405118720.

The previous prime is 81219365369. The next prime is 81219365441. The reversal of 81219365412 is 21456391218.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1811538 + ... + 1855830.

It is an arithmetic number, because the mean of its divisors is an integer number (4045636784).

Almost surely, 2^81219365412 is an apocalyptic number.

81219365412 is a gapful number since it is divisible by the number (82) formed by its first and last digit.

It is an amenable number.

81219365412 is an abundant number, since it is smaller than the sum of its proper divisors (112971200220).

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

81219365412 is a wasteful number, since it uses less digits than its factorization.

81219365412 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 48068 (or 48066 counting only the distinct ones).

The product of its digits is 103680, while the sum is 42.

The spelling of 81219365412 in words is "eighty-one billion, two hundred nineteen million, three hundred sixty-five thousand, four hundred twelve".