768319921 has 2 divisors, whose sum is σ = 768319922. Its totient is φ = 768319920.

The previous prime is 768319919. The next prime is 768319927. The reversal of 768319921 is 129913867.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 632271025 + 136048896 = 25145^2 + 11664^2 .

It is a cyclic number.

It is not a de Polignac number, because 768319921 - 2¹ = 768319919 is a prime.

Together with 768319919, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (768319927) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 384159960 + 384159961.

It is an arithmetic number, because the mean of its divisors is an integer number (384159961).

Almost surely, 2^768319921 is an apocalyptic number.

It is an amenable number.

768319921 is a deficient number, since it is larger than the sum of its proper divisors (1).

768319921 is an equidigital number, since it uses as much as digits as its factorization.

768319921 is an evil number, because the sum of its binary digits is even.

The product of its digits is 163296, while the sum is 46.

The square root of 768319921 is about 27718.5843974760. The cubic root of 768319921 is about 915.8985354614.

The spelling of 768319921 in words is "seven hundred sixty-eight million, three hundred nineteen thousand, nine hundred twenty-one".