77813887 has 2 divisors, whose sum is σ = 77813888. Its totient is φ = 77813886.

The previous prime is 77813881. The next prime is 77813903. The reversal of 77813887 is 78831877.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-77813887 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 77813887.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (77813881) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38906943 + 38906944.

It is an arithmetic number, because the mean of its divisors is an integer number (38906944).

Almost surely, 2^77813887 is an apocalyptic number.

77813887 is a deficient number, since it is larger than the sum of its proper divisors (1).

77813887 is an equidigital number, since it uses as much as digits as its factorization.

77813887 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 526848, while the sum is 49.

The square root of 77813887 is about 8821.2179998003. The cubic root of 77813887 is about 426.9257696104.

The spelling of 77813887 in words is "seventy-seven million, eight hundred thirteen thousand, eight hundred eighty-seven".