81437681003953 has 4 divisors (see below), whose sum is σ = 81656012588788. Its totient is φ = 81219349419120.

The previous prime is 81437681003941. The next prime is 81437681003999. The reversal of 81437681003953 is 35930018673418.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 46047936654769 + 35389744349184 = 6785863^2 + 5948928^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81437681003953 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81437681003153) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 109165791858 + ... + 109165792603.

It is an arithmetic number, because the mean of its divisors is an integer number (20414003147197).

Almost surely, 2^{81437681003953} is an apocalyptic number.

It is an amenable number.

81437681003953 is a deficient number, since it is larger than the sum of its proper divisors (218331584835).

81437681003953 is a wasteful number, since it uses less digits than its factorization.

81437681003953 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 218331584834.

The product of its (nonzero) digits is 13063680, while the sum is 58.

The spelling of 81437681003953 in words is "eighty-one trillion, four hundred thirty-seven billion, six hundred eighty-one million, three thousand, nine hundred fifty-three".