81256303022551 has 4 divisors (see below), whose sum is σ = 81256363174600. Its totient is φ = 81256242870504.

The previous prime is 81256303022497. The next prime is 81256303022567. The reversal of 81256303022551 is 15522030365218.

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

It is a cyclic number.

It is not a de Polignac number, because 81256303022551 - 2²⁵ = 81256269468119 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 81256303022498 and 81256303022507.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81256303022591) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 28002081 + ... + 30767338.

It is an arithmetic number, because the mean of its divisors is an integer number (20314090793650).

Almost surely, 2^{81256303022551} is an apocalyptic number.

81256303022551 is a deficient number, since it is larger than the sum of its proper divisors (60152049).

81256303022551 is a wasteful number, since it uses less digits than its factorization.

81256303022551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 60152048.

The product of its (nonzero) digits is 432000, while the sum is 43.

Adding to 81256303022551 its reverse (15522030365218), we get a palindrome (96778333387769).

The spelling of 81256303022551 in words is "eighty-one trillion, two hundred fifty-six billion, three hundred three million, twenty-two thousand, five hundred fifty-one".