81434507147449 has 27 divisors (see below), whose sum is σ = 86293681594029. Its totient is φ = 76837744355040.

The previous prime is 81434507147333. The next prime is 81434507147501. The reversal of 81434507147449 is 94474170543418.

The square root of 81434507147449 is 9024107.

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

It can be written as a sum of positive squares in 4 ways, for example, as 44715367172025 + 36719139975424 = 6686955^2 + 6059632^2 .

It is not a de Polignac number, because 81434507147449 - 2¹³ = 81434507139257 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81434507147849) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 50237202859 + ... + 50237204479.

Almost surely, 2^{81434507147449} is an apocalyptic number.

81434507147449 is the 9024107-th square number.

81434507147449 is the 4512054-th centered octagonal number.

It is an amenable number.

81434507147449 is a deficient number, since it is larger than the sum of its proper divisors (4859174446580).

81434507147449 is an frugal number, since it uses more digits than its factorization.

81434507147449 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3866 (or 1933 counting only the distinct ones).

The product of its (nonzero) digits is 54190080, while the sum is 61.

The spelling of 81434507147449 in words is "eighty-one trillion, four hundred thirty-four billion, five hundred seven million, one hundred forty-seven thousand, four hundred forty-nine".