1223997779 has 2 divisors, whose sum is σ = 1223997780. Its totient is φ = 1223997778.

The previous prime is 1223997743. The next prime is 1223997799. The reversal of 1223997779 is 9777993221.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1223997779 - 2²⁴ = 1207220563 is a prime.

It is not a weakly prime, because it can be changed into another prime (1223997799) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 611998889 + 611998890.

It is an arithmetic number, because the mean of its divisors is an integer number (611998890).

Almost surely, 2^1223997779 is an apocalyptic number.

1223997779 is a deficient number, since it is larger than the sum of its proper divisors (1).

1223997779 is an equidigital number, since it uses as much as digits as its factorization.

1223997779 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3000564, while the sum is 56.

The square root of 1223997779 is about 34985.6796275276. The cubic root of 1223997779 is about 1069.6956012444.

The spelling of 1223997779 in words is "one billion, two hundred twenty-three million, nine hundred ninety-seven thousand, seven hundred seventy-nine".