780000020221 has 2 divisors, whose sum is σ = 780000020222. Its totient is φ = 780000020220.

The previous prime is 780000020213. The next prime is 780000020231. The reversal of 780000020221 is 122020000087.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 624558284100 + 155441736121 = 790290^2 + 394261^2 .

It is an emirp because it is prime and its reverse (122020000087) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 780000020221 - 2³ = 780000020213 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 780000020192 and 780000020201.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (780000020231) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 390000010110 + 390000010111.

It is an arithmetic number, because the mean of its divisors is an integer number (390000010111).

Almost surely, 2^780000020221 is an apocalyptic number.

It is an amenable number.

780000020221 is a deficient number, since it is larger than the sum of its proper divisors (1).

780000020221 is an equidigital number, since it uses as much as digits as its factorization.

780000020221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 448, while the sum is 22.

The spelling of 780000020221 in words is "seven hundred eighty billion, twenty thousand, two hundred twenty-one".