78139789 has 16 divisors (see below), whose sum is σ = 96519808. Its totient is φ = 61601472.

The previous prime is 78139783. The next prime is 78139793. The reversal of 78139789 is 98793187.

It is a cyclic number.

It is not a de Polignac number, because 78139789 - 2⁵ = 78139757 is a prime.

It is a super-2 number, since 2×78139789² = 12211653249929042, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78139783) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 26539 + ... + 29335.

It is an arithmetic number, because the mean of its divisors is an integer number (6032488).

Almost surely, 2^78139789 is an apocalyptic number.

It is an amenable number.

78139789 is a deficient number, since it is larger than the sum of its proper divisors (18380019).

78139789 is a wasteful number, since it uses less digits than its factorization.

78139789 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3124.

The product of its digits is 762048, while the sum is 52.

The square root of 78139789 is about 8839.6713174190. The cubic root of 78139789 is about 427.5209597238.

The spelling of 78139789 in words is "seventy-eight million, one hundred thirty-nine thousand, seven hundred eighty-nine".