81373645450 has 12 divisors (see below), whose sum is σ = 151354980630. Its totient is φ = 32549458160.

The previous prime is 81373645439. The next prime is 81373645471. The reversal of 81373645450 is 5454637318.

It can be written as a sum of positive squares in 3 ways, for example, as 58462887681 + 22910757769 = 241791^2 + 151363^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 81373645450.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 813736405 + ... + 813736504.

Almost surely, 2^81373645450 is an apocalyptic number.

81373645450 is a deficient number, since it is larger than the sum of its proper divisors (69981335180).

81373645450 is a wasteful number, since it uses less digits than its factorization.

81373645450 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1627472921 (or 1627472916 counting only the distinct ones).

The product of its (nonzero) digits is 1209600, while the sum is 46.

The spelling of 81373645450 in words is "eighty-one billion, three hundred seventy-three million, six hundred forty-five thousand, four hundred fifty".