81356677 has 2 divisors, whose sum is σ = 81356678. Its totient is φ = 81356676.

The previous prime is 81356663. The next prime is 81356711. The reversal of 81356677 is 77665318.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 60980481 + 20376196 = 7809^2 + 4514^2 .

It is a cyclic number.

It is not a de Polignac number, because 81356677 - 2⁷ = 81356549 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81356777) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40678338 + 40678339.

It is an arithmetic number, because the mean of its divisors is an integer number (40678339).

Almost surely, 2^81356677 is an apocalyptic number.

It is an amenable number.

81356677 is a deficient number, since it is larger than the sum of its proper divisors (1).

81356677 is an equidigital number, since it uses as much as digits as its factorization.

81356677 is an evil number, because the sum of its binary digits is even.

The product of its digits is 211680, while the sum is 43.

The square root of 81356677 is about 9019.7936229162. The cubic root of 81356677 is about 433.3090242116.

The spelling of 81356677 in words is "eighty-one million, three hundred fifty-six thousand, six hundred seventy-seven".