81499333 has 2 divisors, whose sum is σ = 81499334. Its totient is φ = 81499332.

The previous prime is 81499321. The next prime is 81499339. The reversal of 81499333 is 33399418.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 55621764 + 25877569 = 7458^2 + 5087^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81499333 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81499339) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40749666 + 40749667.

It is an arithmetic number, because the mean of its divisors is an integer number (40749667).

Almost surely, 2^81499333 is an apocalyptic number.

It is an amenable number.

81499333 is a deficient number, since it is larger than the sum of its proper divisors (1).

81499333 is an equidigital number, since it uses as much as digits as its factorization.

81499333 is an evil number, because the sum of its binary digits is even.

The product of its digits is 69984, while the sum is 40.

The square root of 81499333 is about 9027.6981008450. The cubic root of 81499333 is about 433.5621402433.

The spelling of 81499333 in words is "eighty-one million, four hundred ninety-nine thousand, three hundred thirty-three".