77989209 has 16 divisors (see below), whose sum is σ = 106080000. Its totient is φ = 50951376.

The previous prime is 77989199. The next prime is 77989267. The reversal of 77989209 is 90298977.

It is a happy number.

It is a de Polignac number, because none of the positive numbers 2^k-77989209 is a prime.

It is not an unprimeable number, because it can be changed into a prime (77989909) 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, 87882 + ... + 88764.

It is an arithmetic number, because the mean of its divisors is an integer number (6630000).

Almost surely, 2^77989209 is an apocalyptic number.

It is an amenable number.

77989209 is a deficient number, since it is larger than the sum of its proper divisors (28090791).

77989209 is a wasteful number, since it uses less digits than its factorization.

77989209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1444.

The product of its (nonzero) digits is 571536, while the sum is 51.

The square root of 77989209 is about 8831.1499251230. The cubic root of 77989209 is about 427.2461637312.

The spelling of 77989209 in words is "seventy-seven million, nine hundred eighty-nine thousand, two hundred nine".