77305409 has 4 divisors (see below), whose sum is σ = 81852804. Its totient is φ = 72758016.

The previous prime is 77305391. The next prime is 77305421. The reversal of 77305409 is 90450377.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 90450377 = 103 ⋅878159.

It can be written as a sum of positive squares in 2 ways, for example, as 39753025 + 37552384 = 6305^2 + 6128^2 .

It is a cyclic number.

It is not a de Polignac number, because 77305409 - 2¹² = 77301313 is a prime.

It is a super-2 number, since 2×77305409² = 11952252521314562, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (77305309) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2273672 + ... + 2273705.

It is an arithmetic number, because the mean of its divisors is an integer number (20463201).

Almost surely, 2^77305409 is an apocalyptic number.

It is an amenable number.

77305409 is a deficient number, since it is larger than the sum of its proper divisors (4547395).

77305409 is a wasteful number, since it uses less digits than its factorization.

77305409 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4547394.

The product of its (nonzero) digits is 26460, while the sum is 35.

The square root of 77305409 is about 8792.3494584781. The cubic root of 77305409 is about 425.9938154377.

The spelling of 77305409 in words is "seventy-seven million, three hundred five thousand, four hundred nine".