77492809 has 3 divisors (see below), whose sum is σ = 77501613. Its totient is φ = 77484006.

The previous prime is 77492791. The next prime is 77492873. The reversal of 77492809 is 90829477.

The square root of 77492809 is 8803.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is not a de Polignac number, because 77492809 - 2⁹ = 77492297 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (77492609) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 4402 + ... + 13204.

It is an arithmetic number, because the mean of its divisors is an integer number (25833871).

Almost surely, 2^77492809 is an apocalyptic number.

77492809 is the 8803-rd square number.

77492809 is the 4402-nd centered octagonal number.

It is an amenable number.

77492809 is a deficient number, since it is larger than the sum of its proper divisors (8804).

77492809 is an frugal number, since it uses more digits than its factorization.

77492809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17606 (or 8803 counting only the distinct ones).

The product of its (nonzero) digits is 254016, while the sum is 46.

The cubic root of 77492809 is about 426.3377621339.

Multiplying 77492809 by its product of nonzero digits (254016), we get a square (19684413370944 = 4436712²).

The spelling of 77492809 in words is "seventy-seven million, four hundred ninety-two thousand, eight hundred nine".