1205817797 has 2 divisors, whose sum is σ = 1205817798. Its totient is φ = 1205817796.

The previous prime is 1205817733. The next prime is 1205817799. The reversal of 1205817797 is 7977185021.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 827943076 + 377874721 = 28774^2 + 19439^2 .

It is a cyclic number.

It is not a de Polignac number, because 1205817797 - 2⁶ = 1205817733 is a prime.

Together with 1205817799, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1205817799) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 602908898 + 602908899.

It is an arithmetic number, because the mean of its divisors is an integer number (602908899).

Almost surely, 2^1205817797 is an apocalyptic number.

It is an amenable number.

1205817797 is a deficient number, since it is larger than the sum of its proper divisors (1).

1205817797 is an equidigital number, since it uses as much as digits as its factorization.

1205817797 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 246960, while the sum is 47.

The square root of 1205817797 is about 34724.8872856342. The cubic root of 1205817797 is about 1064.3731157583.

The spelling of 1205817797 in words is "one billion, two hundred five million, eight hundred seventeen thousand, seven hundred ninety-seven".