74187809 has 2 divisors, whose sum is σ = 74187810. Its totient is φ = 74187808.

The previous prime is 74187781. The next prime is 74187823. The reversal of 74187809 is 90878147.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 50694400 + 23493409 = 7120^2 + 4847^2 .

It is an emirp because it is prime and its reverse (90878147) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 74187809 - 2²⁴ = 57410593 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 74187809.

It is not a weakly prime, because it can be changed into another prime (74187859) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 37093904 + 37093905.

It is an arithmetic number, because the mean of its divisors is an integer number (37093905).

Almost surely, 2^74187809 is an apocalyptic number.

It is an amenable number.

74187809 is a deficient number, since it is larger than the sum of its proper divisors (1).

74187809 is an equidigital number, since it uses as much as digits as its factorization.

74187809 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 112896, while the sum is 44.

The square root of 74187809 is about 8613.2345260071. The cubic root of 74187809 is about 420.1885189223.

The spelling of 74187809 in words is "seventy-four million, one hundred eighty-seven thousand, eight hundred nine".