79812869 has 2 divisors, whose sum is σ = 79812870. Its totient is φ = 79812868.

The previous prime is 79812857. The next prime is 79812877. The reversal of 79812869 is 96821897.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 59876644 + 19936225 = 7738^2 + 4465^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-79812869 is a prime.

It is a super-2 number, since 2×79812869² = 12740188116022322, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (79812269) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39906434 + 39906435.

It is an arithmetic number, because the mean of its divisors is an integer number (39906435).

Almost surely, 2^79812869 is an apocalyptic number.

It is an amenable number.

79812869 is a deficient number, since it is larger than the sum of its proper divisors (1).

79812869 is an equidigital number, since it uses as much as digits as its factorization.

79812869 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 435456, while the sum is 50.

The square root of 79812869 is about 8933.8048445217. The cubic root of 79812869 is about 430.5507077754.

Subtracting 79812869 from its reverse (96821897), we obtain a triangular number (17009028 = T₅₈₃₂).

The spelling of 79812869 in words is "seventy-nine million, eight hundred twelve thousand, eight hundred sixty-nine".