823172761 has 2 divisors, whose sum is σ = 823172762. Its totient is φ = 823172760.

The previous prime is 823172741. The next prime is 823172797. The reversal of 823172761 is 167271328.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 637259536 + 185913225 = 25244^2 + 13635^2 .

It is a cyclic number.

It is not a de Polignac number, because 823172761 - 2²³ = 814784153 is a prime.

It is a super-2 number, since 2×823172761² = 1355226788904726242, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 823172761.

It is not a weakly prime, because it can be changed into another prime (823172741) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 411586380 + 411586381.

It is an arithmetic number, because the mean of its divisors is an integer number (411586381).

Almost surely, 2^823172761 is an apocalyptic number.

It is an amenable number.

823172761 is a deficient number, since it is larger than the sum of its proper divisors (1).

823172761 is an equidigital number, since it uses as much as digits as its factorization.

823172761 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 28224, while the sum is 37.

The square root of 823172761 is about 28690.9874525085. The cubic root of 823172761 is about 937.1957928785.

It can be divided in two parts, 82317 and 2761, that added together give a triangular number (85078 = T₄₁₂).

The spelling of 823172761 in words is "eight hundred twenty-three million, one hundred seventy-two thousand, seven hundred sixty-one".