78212929 has 2 divisors, whose sum is σ = 78212930. Its totient is φ = 78212928.

The previous prime is 78212921. The next prime is 78212941. The reversal of 78212929 is 92921287.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 74304400 + 3908529 = 8620^2 + 1977^2 .

It is an emirp because it is prime and its reverse (92921287) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 78212929 - 2³ = 78212921 is a prime.

It is a super-2 number, since 2×78212929² = 12234524525518082, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 78212891 and 78212900.

It is not a weakly prime, because it can be changed into another prime (78212921) 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, 39106464 + 39106465.

It is an arithmetic number, because the mean of its divisors is an integer number (39106465).

Almost surely, 2^78212929 is an apocalyptic number.

It is an amenable number.

78212929 is a deficient number, since it is larger than the sum of its proper divisors (1).

78212929 is an equidigital number, since it uses as much as digits as its factorization.

78212929 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 36288, while the sum is 40.

The square root of 78212929 is about 8843.8073814393. The cubic root of 78212929 is about 427.6543067779.

The spelling of 78212929 in words is "seventy-eight million, two hundred twelve thousand, nine hundred twenty-nine".