13429646581 has 4 divisors (see below), whose sum is σ = 14462696332. Its totient is φ = 12396596832.

The previous prime is 13429646561. The next prime is 13429646599. The reversal of 13429646581 is 18564692431.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 18564692431 = 367 ⋅50584993.

It can be written as a sum of positive squares in 2 ways, for example, as 1663905681 + 11765740900 = 40791^2 + 108470^2 .

It is a cyclic number.

It is not a de Polignac number, because 13429646581 - 2¹⁹ = 13429122293 is a prime.

It is a super-2 number, since 2×13429646581² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13429646551) 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, 516524856 + ... + 516524881.

It is an arithmetic number, because the mean of its divisors is an integer number (3615674083).

Almost surely, 2^13429646581 is an apocalyptic number.

It is an amenable number.

13429646581 is a deficient number, since it is larger than the sum of its proper divisors (1033049751).

13429646581 is a wasteful number, since it uses less digits than its factorization.

13429646581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1033049750.

The product of its digits is 1244160, while the sum is 49.

The spelling of 13429646581 in words is "thirteen billion, four hundred twenty-nine million, six hundred forty-six thousand, five hundred eighty-one".