77731825489 has 4 divisors (see below), whose sum is σ = 77733357156. Its totient is φ = 77730293824.

The previous prime is 77731825477. The next prime is 77731825529. The reversal of 77731825489 is 98452813777.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 98452813777 = 29 ⋅3394924613.

It can be written as a sum of positive squares in 2 ways, for example, as 74275326225 + 3456499264 = 272535^2 + 58792^2 .

It is a cyclic number.

It is not a de Polignac number, because 77731825489 - 2⁷ = 77731825361 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (77731825429) 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, 687004 + ... + 792109.

It is an arithmetic number, because the mean of its divisors is an integer number (19433339289).

Almost surely, 2^77731825489 is an apocalyptic number.

It is an amenable number.

77731825489 is a deficient number, since it is larger than the sum of its proper divisors (1531667).

77731825489 is a wasteful number, since it uses less digits than its factorization.

77731825489 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1531666.

The product of its digits is 23708160, while the sum is 61.

The spelling of 77731825489 in words is "seventy-seven billion, seven hundred thirty-one million, eight hundred twenty-five thousand, four hundred eighty-nine".