81608953 has 2 divisors, whose sum is σ = 81608954. Its totient is φ = 81608952.

The previous prime is 81608927. The next prime is 81608981. The reversal of 81608953 is 35980618.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 54287424 + 27321529 = 7368^2 + 5227^2 .

It is a cyclic number.

It is not a de Polignac number, because 81608953 - 2¹⁷ = 81477881 is a prime.

It is not a weakly prime, because it can be changed into another prime (81608053) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40804476 + 40804477.

It is an arithmetic number, because the mean of its divisors is an integer number (40804477).

Almost surely, 2^81608953 is an apocalyptic number.

It is an amenable number.

81608953 is a deficient number, since it is larger than the sum of its proper divisors (1).

81608953 is an equidigital number, since it uses as much as digits as its factorization.

81608953 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 51840, while the sum is 40.

The square root of 81608953 is about 9033.7673757962. The cubic root of 81608953 is about 433.7564395393.

The spelling of 81608953 in words is "eighty-one million, six hundred eight thousand, nine hundred fifty-three".