77742009 has 12 divisors (see below), whose sum is σ = 112409700. Its totient is φ = 51774624.

The previous prime is 77741987. The next prime is 77742013. The reversal of 77742009 is 90024777.

It can be written as a sum of positive squares in 2 ways, for example, as 18020025 + 59721984 = 4245^2 + 7728^2 .

It is not a de Polignac number, because 77742009 - 2⁸ = 77741753 is a prime.

It is not an unprimeable number, because it can be changed into a prime (77742019) 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, 6087 + ... + 13875.

It is an arithmetic number, because the mean of its divisors is an integer number (9367475).

Almost surely, 2^77742009 is an apocalyptic number.

It is an amenable number.

77742009 is a deficient number, since it is larger than the sum of its proper divisors (34667691).

77742009 is a wasteful number, since it uses less digits than its factorization.

77742009 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8904 (or 8901 counting only the distinct ones).

The product of its (nonzero) digits is 24696, while the sum is 36.

The square root of 77742009 is about 8817.1429045922. The cubic root of 77742009 is about 426.7942762696.

The spelling of 77742009 in words is "seventy-seven million, seven hundred forty-two thousand, nine".