81246223511 has 4 divisors (see below), whose sum is σ = 82274656800. Its totient is φ = 80217790224.

The previous prime is 81246223493. The next prime is 81246223519. The reversal of 81246223511 is 11532264218.

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 81246223511 - 2⁶ = 81246223447 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81246223519) 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, 514216526 + ... + 514216683.

It is an arithmetic number, because the mean of its divisors is an integer number (20568664200).

Almost surely, 2^81246223511 is an apocalyptic number.

81246223511 is a deficient number, since it is larger than the sum of its proper divisors (1028433289).

81246223511 is a wasteful number, since it uses less digits than its factorization.

81246223511 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1028433288.

The product of its digits is 23040, while the sum is 35.

Adding to 81246223511 its reverse (11532264218), we get a palindrome (92778487729).

The spelling of 81246223511 in words is "eighty-one billion, two hundred forty-six million, two hundred twenty-three thousand, five hundred eleven".