77989885 has 4 divisors (see below), whose sum is σ = 93587868. Its totient is φ = 62391904.

The previous prime is 77989883. The next prime is 77989909. The reversal of 77989885 is 58898977.

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 10536516 + 67453369 = 3246^2 + 8213^2 .

It is a cyclic number.

It is not a de Polignac number, because 77989885 - 2¹ = 77989883 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 (77989883) 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, 7798984 + ... + 7798993.

It is an arithmetic number, because the mean of its divisors is an integer number (23396967).

Almost surely, 2^77989885 is an apocalyptic number.

It is an amenable number.

77989885 is a deficient number, since it is larger than the sum of its proper divisors (15597983).

77989885 is a wasteful number, since it uses less digits than its factorization.

77989885 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15597982.

The product of its digits is 10160640, while the sum is 61.

The square root of 77989885 is about 8831.1881986514. The cubic root of 77989885 is about 427.2473981652.

The spelling of 77989885 in words is "seventy-seven million, nine hundred eighty-nine thousand, eight hundred eighty-five".