81409214329 has 9 divisors (see below), whose sum is σ = 85925141967. Its totient is φ = 77119383024.

The previous prime is 81409214317. The next prime is 81409214377. The reversal of 81409214329 is 92341290418.

The square root of 81409214329 is 285323.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 27607484025 + 53801730304 = 166155^2 + 231952^2 .

It is a de Polignac number, because none of the positive numbers 2^k-81409214329 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81409214399) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 5413629 + ... + 5428645.

Almost surely, 2^81409214329 is an apocalyptic number.

81409214329 is the 285323-rd square number.

81409214329 is the 142662-nd centered octagonal number.

It is an amenable number.

81409214329 is a deficient number, since it is larger than the sum of its proper divisors (4515927638).

81409214329 is an frugal number, since it uses more digits than its factorization.

81409214329 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30072 (or 15036 counting only the distinct ones).

The product of its (nonzero) digits is 124416, while the sum is 43.

The spelling of 81409214329 in words is "eighty-one billion, four hundred nine million, two hundred fourteen thousand, three hundred twenty-nine".