77861887 has 16 divisors (see below), whose sum is σ = 84564000. Its totient is φ = 71418880.

The previous prime is 77861881. The next prime is 77861891. The reversal of 77861887 is 78816877.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 77861887 - 2⁷ = 77861759 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 (77861881) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 149187 + ... + 149707.

It is an arithmetic number, because the mean of its divisors is an integer number (5285250).

Almost surely, 2^77861887 is an apocalyptic number.

77861887 is a deficient number, since it is larger than the sum of its proper divisors (6702113).

77861887 is a wasteful number, since it uses less digits than its factorization.

77861887 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 746.

The product of its digits is 1053696, while the sum is 52.

The square root of 77861887 is about 8823.9382930753. The cubic root of 77861887 is about 427.0135355416.

The spelling of 77861887 in words is "seventy-seven million, eight hundred sixty-one thousand, eight hundred eighty-seven".