81625744192 has 28 divisors (see below), whose sum is σ = 162176406660. Its totient is φ = 40762397696.

The previous prime is 81625744139. The next prime is 81625744217. The reversal of 81625744192 is 29144752618.

It can be written as a sum of positive squares in 2 ways, for example, as 69581998656 + 12043745536 = 263784^2 + 109744^2 .

It is a super-2 number, since 2×81625744192² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 736483 + ... + 840034.

Almost surely, 2^81625744192 is an apocalyptic number.

It is an amenable number.

81625744192 is a deficient number, since it is larger than the sum of its proper divisors (80550662468).

81625744192 is a wasteful number, since it uses less digits than its factorization.

81625744192 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1577338 (or 1577328 counting only the distinct ones).

The product of its digits is 967680, while the sum is 49.

The spelling of 81625744192 in words is "eighty-one billion, six hundred twenty-five million, seven hundred forty-four thousand, one hundred ninety-two".