81682553 has 2 divisors, whose sum is σ = 81682554. Its totient is φ = 81682552.

The previous prime is 81682543. The next prime is 81682597. The reversal of 81682553 is 35528618.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 60264169 + 21418384 = 7763^2 + 4628^2 .

It is a cyclic number.

It is not a de Polignac number, because 81682553 - 2²⁰ = 80633977 is a prime.

It is not a weakly prime, because it can be changed into another prime (81682543) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40841276 + 40841277.

It is an arithmetic number, because the mean of its divisors is an integer number (40841277).

Almost surely, 2^81682553 is an apocalyptic number.

It is an amenable number.

81682553 is a deficient number, since it is larger than the sum of its proper divisors (1).

81682553 is an equidigital number, since it uses as much as digits as its factorization.

81682553 is an evil number, because the sum of its binary digits is even.

The product of its digits is 57600, while the sum is 38.

The square root of 81682553 is about 9037.8400627584. The cubic root of 81682553 is about 433.8867964852.

The spelling of 81682553 in words is "eighty-one million, six hundred eighty-two thousand, five hundred fifty-three".