820142761 has 2 divisors, whose sum is σ = 820142762. Its totient is φ = 820142760.

The previous prime is 820142749. The next prime is 820142767. The reversal of 820142761 is 167241028.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 819104400 + 1038361 = 28620^2 + 1019^2 .

It is a cyclic number.

It is not a de Polignac number, because 820142761 - 2²⁵ = 786588329 is a prime.

It is not a weakly prime, because it can be changed into another prime (820142767) 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, 410071380 + 410071381.

It is an arithmetic number, because the mean of its divisors is an integer number (410071381).

Almost surely, 2^820142761 is an apocalyptic number.

It is an amenable number.

820142761 is a deficient number, since it is larger than the sum of its proper divisors (1).

820142761 is an equidigital number, since it uses as much as digits as its factorization.

820142761 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5376, while the sum is 31.

The square root of 820142761 is about 28638.1347332538. The cubic root of 820142761 is about 936.0444774108.

Adding to 820142761 its reverse (167241028), we get a palindrome (987383789).

The spelling of 820142761 in words is "eight hundred twenty million, one hundred forty-two thousand, seven hundred sixty-one".