77620509 has 12 divisors (see below), whose sum is σ = 112276476. Its totient is φ = 51674112.

The previous prime is 77620489. The next prime is 77620511. The reversal of 77620509 is 90502677.

It can be written as a sum of positive squares in 2 ways, for example, as 52969284 + 24651225 = 7278^2 + 4965^2 .

It is not a de Polignac number, because 77620509 - 2¹⁷ = 77489437 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77620579) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1117 + ... + 12509.

It is an arithmetic number, because the mean of its divisors is an integer number (9356373).

Almost surely, 2^77620509 is an apocalyptic number.

It is an amenable number.

77620509 is a deficient number, since it is larger than the sum of its proper divisors (34655967).

77620509 is a wasteful number, since it uses less digits than its factorization.

77620509 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12156 (or 12153 counting only the distinct ones).

The product of its (nonzero) digits is 26460, while the sum is 36.

The square root of 77620509 is about 8810.2502234613. The cubic root of 77620509 is about 426.5718202126.

The spelling of 77620509 in words is "seventy-seven million, six hundred twenty thousand, five hundred nine".