81716477 has 2 divisors, whose sum is σ = 81716478. Its totient is φ = 81716476.

The previous prime is 81716449. The next prime is 81716581. The reversal of 81716477 is 77461718.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 72267001 + 9449476 = 8501^2 + 3074^2 .

It is a cyclic number.

It is not a de Polignac number, because 81716477 - 2⁶ = 81716413 is a prime.

It is a super-2 number, since 2×81716477² = 13355165226583058, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81716177) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40858238 + 40858239.

It is an arithmetic number, because the mean of its divisors is an integer number (40858239).

Almost surely, 2^81716477 is an apocalyptic number.

It is an amenable number.

81716477 is a deficient number, since it is larger than the sum of its proper divisors (1).

81716477 is an equidigital number, since it uses as much as digits as its factorization.

81716477 is an evil number, because the sum of its binary digits is even.

The product of its digits is 65856, while the sum is 41.

The square root of 81716477 is about 9039.7166437892. The cubic root of 81716477 is about 433.9468547551.

The spelling of 81716477 in words is "eighty-one million, seven hundred sixteen thousand, four hundred seventy-seven".