838779390801 has 125 divisors (see below), whose sum is σ = 1427506309405. Its totient is φ = 490821796080.

The previous prime is 838779390767. The next prime is 838779390809. The reversal of 838779390801 is 108093977838.

The square root of 838779390801 is 915849.

It is a perfect power (a square, a biquadrate), and thus also a powerful number.

838779390801 is a `hidden beast` number, since 8 + 387 + 7 + 93 + 90 + 80 + 1 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 1993533201 + 836785857600 = 44649^2 + 914760^2 .

It is not a de Polignac number, because 838779390801 - 2¹⁷ = 838779259729 is a prime.

It is not an unprimeable number, because it can be changed into a prime (838779390809) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 124 ways as a sum of consecutive naturals, for example, 28923427255 + ... + 28923427283.

Almost surely, 2^838779390801 is an apocalyptic number.

838779390801 is a gapful number since it is divisible by the number (81) formed by its first and last digit.

838779390801 is the 915849-th square number.

838779390801 is the 457925-th centered octagonal number.

It is an amenable number.

838779390801 is a deficient number, since it is larger than the sum of its proper divisors (588726918604).

838779390801 is an frugal number, since it uses more digits than its factorization.

838779390801 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 172 (or 43 counting only the distinct ones).

The product of its (nonzero) digits is 18289152, while the sum is 63.

The spelling of 838779390801 in words is "eight hundred thirty-eight billion, seven hundred seventy-nine million, three hundred ninety thousand, eight hundred one".