81240653045 has 4 divisors (see below), whose sum is σ = 97488783660. Its totient is φ = 64992522432.

The previous prime is 81240653027. The next prime is 81240653057. The reversal of 81240653045 is 54035604218.

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

It can be written as a sum of positive squares in 2 ways, for example, as 49496460484 + 31744192561 = 222478^2 + 178169^2 .

It is a cyclic number.

It is not a de Polignac number, because 81240653045 - 2¹⁰ = 81240652021 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8124065300 + ... + 8124065309.

It is an arithmetic number, because the mean of its divisors is an integer number (24372195915).

Almost surely, 2^81240653045 is an apocalyptic number.

It is an amenable number.

81240653045 is a deficient number, since it is larger than the sum of its proper divisors (16248130615).

81240653045 is a wasteful number, since it uses less digits than its factorization.

81240653045 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16248130614.

The product of its (nonzero) digits is 115200, while the sum is 38.

The spelling of 81240653045 in words is "eighty-one billion, two hundred forty million, six hundred fifty-three thousand, forty-five".