81157602833 has 2 divisors, whose sum is σ = 81157602834. Its totient is φ = 81157602832.

The previous prime is 81157602817. The next prime is 81157602847. The reversal of 81157602833 is 33820675118.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 76114188544 + 5043414289 = 275888^2 + 71017^2 .

It is a cyclic number.

It is not a de Polignac number, because 81157602833 - 2⁴ = 81157602817 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (81157602803) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40578801416 + 40578801417.

It is an arithmetic number, because the mean of its divisors is an integer number (40578801417).

Almost surely, 2^81157602833 is an apocalyptic number.

It is an amenable number.

81157602833 is a deficient number, since it is larger than the sum of its proper divisors (1).

81157602833 is an equidigital number, since it uses as much as digits as its factorization.

81157602833 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 241920, while the sum is 44.

The spelling of 81157602833 in words is "eighty-one billion, one hundred fifty-seven million, six hundred two thousand, eight hundred thirty-three".