81946633 has 2 divisors, whose sum is σ = 81946634. Its totient is φ = 81946632.

The previous prime is 81946619. The next prime is 81946637. The reversal of 81946633 is 33664918.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 70023424 + 11923209 = 8368^2 + 3453^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81946633 is a prime.

It is not a weakly prime, because it can be changed into another prime (81946637) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40973316 + 40973317.

It is an arithmetic number, because the mean of its divisors is an integer number (40973317).

Almost surely, 2^81946633 is an apocalyptic number.

It is an amenable number.

81946633 is a deficient number, since it is larger than the sum of its proper divisors (1).

81946633 is an equidigital number, since it uses as much as digits as its factorization.

81946633 is an evil number, because the sum of its binary digits is even.

The product of its digits is 93312, while the sum is 40.

The square root of 81946633 is about 9052.4379589147. The cubic root of 81946633 is about 434.3538793657.

The spelling of 81946633 in words is "eighty-one million, nine hundred forty-six thousand, six hundred thirty-three".