81677413 has 2 divisors, whose sum is σ = 81677414. Its totient is φ = 81677412.

The previous prime is 81677411. The next prime is 81677423. The reversal of 81677413 is 31477618.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 61183684 + 20493729 = 7822^2 + 4527^2 .

It is a cyclic number.

It is not a de Polignac number, because 81677413 - 2¹ = 81677411 is a prime.

Together with 81677411, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81677411) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40838706 + 40838707.

It is an arithmetic number, because the mean of its divisors is an integer number (40838707).

Almost surely, 2^81677413 is an apocalyptic number.

It is an amenable number.

81677413 is a deficient number, since it is larger than the sum of its proper divisors (1).

81677413 is an equidigital number, since it uses as much as digits as its factorization.

81677413 is an evil number, because the sum of its binary digits is even.

The product of its digits is 28224, while the sum is 37.

The square root of 81677413 is about 9037.5556983069. Note that the first 3 decimals coincide. The cubic root of 81677413 is about 433.8776952967.

The spelling of 81677413 in words is "eighty-one million, six hundred seventy-seven thousand, four hundred thirteen".