78189129 has 12 divisors (see below), whose sum is σ = 114792132. Its totient is φ = 51271200.

The previous prime is 78189127. The next prime is 78189131. The reversal of 78189129 is 92198187.

It is an interprime number because it is at equal distance from previous prime (78189127) and next prime (78189131).

It can be written as a sum of positive squares in 2 ways, for example, as 23503104 + 54686025 = 4848^2 + 7395^2 .

It is not a de Polignac number, because 78189129 - 2¹ = 78189127 is a prime.

It is a super-2 number, since 2×78189129² = 12227079787557282, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (78189127) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 70662 + ... + 71759.

It is an arithmetic number, because the mean of its divisors is an integer number (9566011).

Almost surely, 2^78189129 is an apocalyptic number.

It is an amenable number.

78189129 is a deficient number, since it is larger than the sum of its proper divisors (36603003).

78189129 is a wasteful number, since it uses less digits than its factorization.

78189129 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 142488 (or 142485 counting only the distinct ones).

The product of its digits is 72576, while the sum is 45.

The square root of 78189129 is about 8842.4617047517. The cubic root of 78189129 is about 427.6109243295.

The spelling of 78189129 in words is "seventy-eight million, one hundred eighty-nine thousand, one hundred twenty-nine".