77721055 has 16 divisors (see below), whose sum is σ = 95948064. Its totient is φ = 60411520.

The previous prime is 77721047. The next prime is 77721067. The reversal of 77721055 is 55012777.

It is not a de Polignac number, because 77721055 - 2³ = 77721047 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 77721055.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 26985 + ... + 29725.

It is an arithmetic number, because the mean of its divisors is an integer number (5996754).

Almost surely, 2^77721055 is an apocalyptic number.

77721055 is a deficient number, since it is larger than the sum of its proper divisors (18227009).

77721055 is a wasteful number, since it uses less digits than its factorization.

77721055 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2906.

The product of its (nonzero) digits is 17150, while the sum is 34.

The square root of 77721055 is about 8815.9545711171. The cubic root of 77721055 is about 426.7559278444.

The spelling of 77721055 in words is "seventy-seven million, seven hundred twenty-one thousand, fifty-five".