81225088342661 has 16 divisors (see below), whose sum is σ = 82629177183168. Its totient is φ = 79826694393600.

The previous prime is 81225088342639. The next prime is 81225088342681. The reversal of 81225088342661 is 16624388052218.

It is a cyclic number.

It is not a de Polignac number, because 81225088342661 - 2¹⁸ = 81225088080517 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 81225088342597 and 81225088342606.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81225088342621) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 199975766 + ... + 200381528.

It is an arithmetic number, because the mean of its divisors is an integer number (5164323573948).

Almost surely, 2^{81225088342661} is an apocalyptic number.

It is an amenable number.

81225088342661 is a deficient number, since it is larger than the sum of its proper divisors (1404088840507).

81225088342661 is a wasteful number, since it uses less digits than its factorization.

81225088342661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 412772.

The product of its (nonzero) digits is 8847360, while the sum is 56.

The spelling of 81225088342661 in words is "eighty-one trillion, two hundred twenty-five billion, eighty-eight million, three hundred forty-two thousand, six hundred sixty-one".