81553703453 has 4 divisors (see below), whose sum is σ = 81554274780. Its totient is φ = 81553132128.

The previous prime is 81553703431. The next prime is 81553703467. The reversal of 81553703453 is 35430735518.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 1533740569 + 80019962884 = 39163^2 + 282878^2 .

It is a cyclic number.

It is not a de Polignac number, because 81553703453 - 2⁶ = 81553703389 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 (81553703423) 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, 132263 + ... + 424971.

It is an arithmetic number, because the mean of its divisors is an integer number (20388568695).

Almost surely, 2^81553703453 is an apocalyptic number.

It is an amenable number.

81553703453 is a deficient number, since it is larger than the sum of its proper divisors (571327).

81553703453 is a wasteful number, since it uses less digits than its factorization.

81553703453 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 571326.

The product of its (nonzero) digits is 756000, while the sum is 44.

The spelling of 81553703453 in words is "eighty-one billion, five hundred fifty-three million, seven hundred three thousand, four hundred fifty-three".