81405066253 has 16 divisors (see below), whose sum is σ = 98522227584. Its totient is φ = 65661143040.

The previous prime is 81405066241. The next prime is 81405066277. The reversal of 81405066253 is 35266050418.

It is a cyclic number.

It is not a de Polignac number, because 81405066253 - 2²¹ = 81402969101 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81405066233) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 772413 + ... + 871453.

It is an arithmetic number, because the mean of its divisors is an integer number (6157639224).

Almost surely, 2^81405066253 is an apocalyptic number.

It is an amenable number.

81405066253 is a deficient number, since it is larger than the sum of its proper divisors (17117161331).

81405066253 is a wasteful number, since it uses less digits than its factorization.

81405066253 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 105972.

The product of its (nonzero) digits is 172800, while the sum is 40.

The spelling of 81405066253 in words is "eighty-one billion, four hundred five million, sixty-six thousand, two hundred fifty-three".