81137412451 has 4 divisors (see below), whose sum is σ = 85407802600. Its totient is φ = 76867022304.

The previous prime is 81137412431. The next prime is 81137412469. The reversal of 81137412451 is 15421473118.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81137412451 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 81137412451.

It is not an unprimeable number, because it can be changed into a prime (81137412431) 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, 2135195046 + ... + 2135195083.

It is an arithmetic number, because the mean of its divisors is an integer number (21351950650).

Almost surely, 2^81137412451 is an apocalyptic number.

81137412451 is a deficient number, since it is larger than the sum of its proper divisors (4270390149).

81137412451 is a wasteful number, since it uses less digits than its factorization.

81137412451 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4270390148.

The product of its digits is 26880, while the sum is 37.

Adding to 81137412451 its reverse (15421473118), we get a palindrome (96558885569).

The spelling of 81137412451 in words is "eighty-one billion, one hundred thirty-seven million, four hundred twelve thousand, four hundred fifty-one".