77428289 has 8 divisors (see below), whose sum is σ = 80510760. Its totient is φ = 74373376.

The previous prime is 77428277. The next prime is 77428301. The reversal of 77428289 is 98282477.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (77428277) and next prime (77428301).

It can be written as a sum of positive squares in 4 ways, for example, as 45697600 + 31730689 = 6760^2 + 5633^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 77428289 - 2⁸ = 77428033 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (77427289) 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 7 ways as a sum of consecutive naturals, for example, 1064 + ... + 12489.

It is an arithmetic number, because the mean of its divisors is an integer number (10063845).

Almost surely, 2^77428289 is an apocalyptic number.

It is an amenable number.

77428289 is a deficient number, since it is larger than the sum of its proper divisors (3082471).

77428289 is a wasteful number, since it uses less digits than its factorization.

77428289 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13779.

The product of its digits is 451584, while the sum is 47.

The square root of 77428289 is about 8799.3345771143. The cubic root of 77428289 is about 426.2194072808.

The spelling of 77428289 in words is "seventy-seven million, four hundred twenty-eight thousand, two hundred eighty-nine".