81474553 has 2 divisors, whose sum is σ = 81474554. Its totient is φ = 81474552.

The previous prime is 81474539. The next prime is 81474563. The reversal of 81474553 is 35547418.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 43983424 + 37491129 = 6632^2 + 6123^2 .

It is a cyclic number.

It is not a de Polignac number, because 81474553 - 2⁵ = 81474521 is a prime.

It is not a weakly prime, because it can be changed into another prime (81474563) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40737276 + 40737277.

It is an arithmetic number, because the mean of its divisors is an integer number (40737277).

Almost surely, 2^81474553 is an apocalyptic number.

It is an amenable number.

81474553 is a deficient number, since it is larger than the sum of its proper divisors (1).

81474553 is an equidigital number, since it uses as much as digits as its factorization.

81474553 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 67200, while the sum is 37.

The square root of 81474553 is about 9026.3255536237. The cubic root of 81474553 is about 433.5181940395.

The spelling of 81474553 in words is "eighty-one million, four hundred seventy-four thousand, five hundred fifty-three".