838860721 has 2 divisors, whose sum is σ = 838860722. Its totient is φ = 838860720.

The previous prime is 838860709. The next prime is 838860769. The reversal of 838860721 is 127068838.

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., 450967696 + 387893025 = 21236^2 + 19695^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-838860721 is a prime.

It is not a weakly prime, because it can be changed into another prime (838860791) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 419430360 + 419430361.

It is an arithmetic number, because the mean of its divisors is an integer number (419430361).

Almost surely, 2^838860721 is an apocalyptic number.

It is an amenable number.

838860721 is a deficient number, since it is larger than the sum of its proper divisors (1).

838860721 is an equidigital number, since it uses as much as digits as its factorization.

838860721 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 129024, while the sum is 43.

The square root of 838860721 is about 28963.0923935964. The cubic root of 838860721 is about 943.1120340460.

The spelling of 838860721 in words is "eight hundred thirty-eight million, eight hundred sixty thousand, seven hundred twenty-one".