77812969 has 4 divisors (see below), whose sum is σ = 83798596. Its totient is φ = 71827344.

The previous prime is 77812939. The next prime is 77812981. The reversal of 77812969 is 96921877.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 5817744 + 71995225 = 2412^2 + 8485^2 .

It is a cyclic number.

It is not a de Polignac number, because 77812969 - 2⁵ = 77812937 is a prime.

It is a super-2 number, since 2×77812969² = 12109716289189922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (77812919) 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 3 ways as a sum of consecutive naturals, for example, 2992794 + ... + 2992819.

It is an arithmetic number, because the mean of its divisors is an integer number (20949649).

Almost surely, 2^77812969 is an apocalyptic number.

It is an amenable number.

77812969 is a deficient number, since it is larger than the sum of its proper divisors (5985627).

77812969 is a wasteful number, since it uses less digits than its factorization.

77812969 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5985626.

The product of its digits is 381024, while the sum is 49.

The square root of 77812969 is about 8821.1659660161. The cubic root of 77812969 is about 426.9240907353.

The spelling of 77812969 in words is "seventy-seven million, eight hundred twelve thousand, nine hundred sixty-nine".