81224448392 has 48 divisors (see below), whose sum is σ = 166275981900. Its totient is φ = 37147985280.

The previous prime is 81224448379. The next prime is 81224448413. The reversal of 81224448392 is 29384442218.

It can be written as a sum of positive squares in 2 ways, for example, as 72648577156 + 8575871236 = 269534^2 + 92606^2 .

It is a super-2 number, since 2×81224448392² (a number of 23 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 401159 + ... + 568662.

Almost surely, 2^81224448392 is an apocalyptic number.

It is an amenable number.

81224448392 is an abundant number, since it is smaller than the sum of its proper divisors (85051533508).

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

81224448392 is a wasteful number, since it uses less digits than its factorization.

81224448392 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 969894 (or 969871 counting only the distinct ones).

The product of its digits is 884736, while the sum is 47.

The spelling of 81224448392 in words is "eighty-one billion, two hundred twenty-four million, four hundred forty-eight thousand, three hundred ninety-two".