81225886742 has 48 divisors (see below), whose sum is σ = 166509039312. Its totient is φ = 29212102080.

The previous prime is 81225886733. The next prime is 81225886771. The reversal of 81225886742 is 24768852218.

It is a happy number.

It is a super-2 number, since 2×81225886742² (a number of 23 digits) contains 22 as substring.

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 in 23 ways as a sum of consecutive naturals, for example, 2884013 + ... + 2912040.

It is an arithmetic number, because the mean of its divisors is an integer number (3468938319).

Almost surely, 2^81225886742 is an apocalyptic number.

81225886742 is an abundant number, since it is smaller than the sum of its proper divisors (85283152570).

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

81225886742 is a wasteful number, since it uses less digits than its factorization.

81225886742 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5796093 (or 5796086 counting only the distinct ones).

The product of its digits is 3440640, while the sum is 53.

The spelling of 81225886742 in words is "eighty-one billion, two hundred twenty-five million, eight hundred eighty-six thousand, seven hundred forty-two".