78438069 has 24 divisors (see below), whose sum is σ = 117656760. Its totient is φ = 50295168.

The previous prime is 78438067. The next prime is 78438097. The reversal of 78438069 is 96083487.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 21511044 + 56927025 = 4638^2 + 7545^2 .

It is not a de Polignac number, because 78438069 - 2¹ = 78438067 is a prime.

It is a super-2 number, since 2×78438069² = 12305061336897522, which contains 22 as substring.

It is a plaindrome in base 13.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78438067) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 103239 + ... + 103995.

It is an arithmetic number, because the mean of its divisors is an integer number (4902365).

Almost surely, 2^78438069 is an apocalyptic number.

It is an amenable number.

78438069 is a deficient number, since it is larger than the sum of its proper divisors (39218691).

78438069 is a wasteful number, since it uses less digits than its factorization.

78438069 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1189 (or 1186 counting only the distinct ones).

The product of its (nonzero) digits is 290304, while the sum is 45.

The square root of 78438069 is about 8856.5269152191. The cubic root of 78438069 is about 428.0642554270.

The spelling of 78438069 in words is "seventy-eight million, four hundred thirty-eight thousand, sixty-nine".