78289489 has 2 divisors, whose sum is σ = 78289490. Its totient is φ = 78289488.

The previous prime is 78289483. The next prime is 78289571. The reversal of 78289489 is 98498287.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 55249489 + 23040000 = 7433^2 + 4800^2 .

It is an emirp because it is prime and its reverse (98498287) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 78289489 - 2¹³ = 78281297 is a prime.

It is a super-2 number, since 2×78289489² = 12258488175762242, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (78289483) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39144744 + 39144745.

It is an arithmetic number, because the mean of its divisors is an integer number (39144745).

Almost surely, 2^78289489 is an apocalyptic number.

It is an amenable number.

78289489 is a deficient number, since it is larger than the sum of its proper divisors (1).

78289489 is an equidigital number, since it uses as much as digits as its factorization.

78289489 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2322432, while the sum is 55.

The square root of 78289489 is about 8848.1347751941. The cubic root of 78289489 is about 427.7938000683.

The spelling of 78289489 in words is "seventy-eight million, two hundred eighty-nine thousand, four hundred eighty-nine".