861428779 has 2 divisors, whose sum is σ = 861428780. Its totient is φ = 861428778.

The previous prime is 861428753. The next prime is 861428801. The reversal of 861428779 is 977824168.

861428779 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 861428779 - 2⁵ = 861428747 is a prime.

It is a super-3 number, since 3×861428779³ (a number of 28 digits) contains 333 as substring.

It is not a weakly prime, because it can be changed into another prime (861438779) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 430714389 + 430714390.

It is an arithmetic number, because the mean of its divisors is an integer number (430714390).

Almost surely, 2^861428779 is an apocalyptic number.

861428779 is a deficient number, since it is larger than the sum of its proper divisors (1).

861428779 is an equidigital number, since it uses as much as digits as its factorization.

861428779 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1354752, while the sum is 52.

The square root of 861428779 is about 29350.1069674371. The cubic root of 861428779 is about 951.4948870915.

The spelling of 861428779 in words is "eight hundred sixty-one million, four hundred twenty-eight thousand, seven hundred seventy-nine".