81464413 has 6 divisors (see below), whose sum is σ = 85160894. Its totient is φ = 77921976.

The previous prime is 81464407. The next prime is 81464443. The reversal of 81464413 is 31446418.

It can be written as a sum of positive squares in only one way, i.e., 76790169 + 4674244 = 8763^2 + 2162^2 .

It is a de Polignac number, because none of the positive numbers 2^k-81464413 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 (81464443) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 76470 + ... + 77527.

Almost surely, 2^81464413 is an apocalyptic number.

It is an amenable number.

81464413 is a deficient number, since it is larger than the sum of its proper divisors (3696481).

81464413 is a wasteful number, since it uses less digits than its factorization.

81464413 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 154043 (or 154020 counting only the distinct ones).

The product of its digits is 9216, while the sum is 31.

The square root of 81464413 is about 9025.7638457917. The cubic root of 81464413 is about 433.5002086412.

The spelling of 81464413 in words is "eighty-one million, four hundred sixty-four thousand, four hundred thirteen".