1321007777 has 2 divisors, whose sum is σ = 1321007778. Its totient is φ = 1321007776.

The previous prime is 1321007747. The next prime is 1321007791. The reversal of 1321007777 is 7777001231.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 997043776 + 323964001 = 31576^2 + 17999^2 .

It is an emirp because it is prime and its reverse (7777001231) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1321007777 - 2¹⁴ = 1320991393 is a prime.

It is not a weakly prime, because it can be changed into another prime (1321007747) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 660503888 + 660503889.

It is an arithmetic number, because the mean of its divisors is an integer number (660503889).

Almost surely, 2^1321007777 is an apocalyptic number.

It is an amenable number.

1321007777 is a deficient number, since it is larger than the sum of its proper divisors (1).

1321007777 is an equidigital number, since it uses as much as digits as its factorization.

1321007777 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 14406, while the sum is 35.

The square root of 1321007777 is about 36345.6706775374. The cubic root of 1321007777 is about 1097.2404042143.

The spelling of 1321007777 in words is "one billion, three hundred twenty-one million, seven thousand, seven hundred seventy-seven".