81135140251 has 8 divisors (see below), whose sum is σ = 88515364608. Its totient is φ = 73755633000.

The previous prime is 81135140249. The next prime is 81135140267. The reversal of 81135140251 is 15204153118.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 81135140251 - 2¹ = 81135140249 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81135140231) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 72706 + ... + 409336.

It is an arithmetic number, because the mean of its divisors is an integer number (11064420576).

Almost surely, 2^81135140251 is an apocalyptic number.

81135140251 is a deficient number, since it is larger than the sum of its proper divisors (7380224357).

81135140251 is a wasteful number, since it uses less digits than its factorization.

81135140251 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 358553.

The product of its (nonzero) digits is 4800, while the sum is 31.

Adding to 81135140251 its reverse (15204153118), we get a palindrome (96339293369).

The spelling of 81135140251 in words is "eighty-one billion, one hundred thirty-five million, one hundred forty thousand, two hundred fifty-one".