81476761 has 2 divisors, whose sum is σ = 81476762. Its totient is φ = 81476760.

The previous prime is 81476749. The next prime is 81476779. The reversal of 81476761 is 16767418.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 72590400 + 8886361 = 8520^2 + 2981^2 .

It is a cyclic number.

It is not a de Polignac number, because 81476761 - 2²³ = 73088153 is a prime.

It is a super-2 number, since 2×81476761² = 13276925166102242, which contains 22 as substring.

It is an alternating number because its digits alternate between even and odd.

It is not a weakly prime, because it can be changed into another prime (81476261) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40738380 + 40738381.

It is an arithmetic number, because the mean of its divisors is an integer number (40738381).

Almost surely, 2^81476761 is an apocalyptic number.

It is an amenable number.

81476761 is a deficient number, since it is larger than the sum of its proper divisors (1).

81476761 is an equidigital number, since it uses as much as digits as its factorization.

81476761 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 56448, while the sum is 40.

The square root of 81476761 is about 9026.4478617006. The cubic root of 81476761 is about 433.5221101887.

The spelling of 81476761 in words is "eighty-one million, four hundred seventy-six thousand, seven hundred sixty-one".