77145989 has 4 divisors (see below), whose sum is σ = 77335020. Its totient is φ = 76956960.

The previous prime is 77145977. The next prime is 77145997. The reversal of 77145989 is 98954177.

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 70845889 + 6300100 = 8417^2 + 2510^2 .

It is a cyclic number.

It is not a de Polignac number, because 77145989 - 2¹⁶ = 77080453 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77145919) 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, 93902 + ... + 94719.

It is an arithmetic number, because the mean of its divisors is an integer number (19333755).

Almost surely, 2^77145989 is an apocalyptic number.

It is an amenable number.

77145989 is a deficient number, since it is larger than the sum of its proper divisors (189031).

77145989 is a wasteful number, since it uses less digits than its factorization.

77145989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 189030.

The product of its digits is 635040, while the sum is 50.

The square root of 77145989 is about 8783.2789435381. The cubic root of 77145989 is about 425.7007843230.

The spelling of 77145989 in words is "seventy-seven million, one hundred forty-five thousand, nine hundred eighty-nine".