78022120021 has 2 divisors, whose sum is σ = 78022120022. Its totient is φ = 78022120020.

The previous prime is 78022120003. The next prime is 78022120079. The reversal of 78022120021 is 12002122087.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 63121035121 + 14901084900 = 251239^2 + 122070^2 .

It is an emirp because it is prime and its reverse (12002122087) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 78022120021 - 2¹³ = 78022111829 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78022120081) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39011060010 + 39011060011.

It is an arithmetic number, because the mean of its divisors is an integer number (39011060011).

Almost surely, 2^78022120021 is an apocalyptic number.

It is an amenable number.

78022120021 is a deficient number, since it is larger than the sum of its proper divisors (1).

78022120021 is an equidigital number, since it uses as much as digits as its factorization.

78022120021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 896, while the sum is 25.

The spelling of 78022120021 in words is "seventy-eight billion, twenty-two million, one hundred twenty thousand, twenty-one".