77469809 has 2 divisors, whose sum is σ = 77469810. Its totient is φ = 77469808.

The previous prime is 77469781. The next prime is 77469827. The reversal of 77469809 is 90896477.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 69472225 + 7997584 = 8335^2 + 2828^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-77469809 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (77469709) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38734904 + 38734905.

It is an arithmetic number, because the mean of its divisors is an integer number (38734905).

Almost surely, 2^77469809 is an apocalyptic number.

It is an amenable number.

77469809 is a deficient number, since it is larger than the sum of its proper divisors (1).

77469809 is an equidigital number, since it uses as much as digits as its factorization.

77469809 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 762048, while the sum is 50.

The square root of 77469809 is about 8801.6935302247. The cubic root of 77469809 is about 426.2955786981.

The spelling of 77469809 in words is "seventy-seven million, four hundred sixty-nine thousand, eight hundred nine".