780320221 has 2 divisors, whose sum is σ = 780320222. Its totient is φ = 780320220.

The previous prime is 780320161. The next prime is 780320263. The reversal of 780320221 is 122023087.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 490844025 + 289476196 = 22155^2 + 17014^2 .

It is an emirp because it is prime and its reverse (122023087) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 780320221 - 2²³ = 771931613 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (780320921) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 390160110 + 390160111.

It is an arithmetic number, because the mean of its divisors is an integer number (390160111).

Almost surely, 2^780320221 is an apocalyptic number.

It is an amenable number.

780320221 is a deficient number, since it is larger than the sum of its proper divisors (1).

780320221 is an equidigital number, since it uses as much as digits as its factorization.

780320221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1344, while the sum is 25.

The square root of 780320221 is about 27934.2123747923. The cubic root of 780320221 is about 920.6423605404.

The spelling of 780320221 in words is "seven hundred eighty million, three hundred twenty thousand, two hundred twenty-one".