78231789 has 6 divisors (see below), whose sum is σ = 113001486. Its totient is φ = 52154520.

The previous prime is 78231787. The next prime is 78231793. The reversal of 78231789 is 98713287.

It can be written as a sum of positive squares in only one way, i.e., 55621764 + 22610025 = 7458^2 + 4755^2 .

It is not a de Polignac number, because 78231789 - 2¹ = 78231787 is a prime.

It is a super-2 number, since 2×78231789² = 12240425620281042, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78231781) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 4346202 + ... + 4346219.

It is an arithmetic number, because the mean of its divisors is an integer number (18833581).

Almost surely, 2^78231789 is an apocalyptic number.

It is an amenable number.

78231789 is a deficient number, since it is larger than the sum of its proper divisors (34769697).

78231789 is a wasteful number, since it uses less digits than its factorization.

78231789 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8692427 (or 8692424 counting only the distinct ones).

The product of its digits is 169344, while the sum is 45.

The square root of 78231789 is about 8844.8736000013. The cubic root of 78231789 is about 427.6886783842.

The spelling of 78231789 in words is "seventy-eight million, two hundred thirty-one thousand, seven hundred eighty-nine".