77078221 has 16 divisors (see below), whose sum is σ = 92907648. Its totient is φ = 63078400.

The previous prime is 77078219. The next prime is 77078227. The reversal of 77078221 is 12287077.

It is not a de Polignac number, because 77078221 - 2¹ = 77078219 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 (77078227) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4660 + ... + 13261.

It is an arithmetic number, because the mean of its divisors is an integer number (5806728).

Almost surely, 2^77078221 is an apocalyptic number.

It is an amenable number.

77078221 is a deficient number, since it is larger than the sum of its proper divisors (15829427).

77078221 is a wasteful number, since it uses less digits than its factorization.

77078221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17972.

The product of its (nonzero) digits is 10976, while the sum is 34.

The square root of 77078221 is about 8779.4203111595. The cubic root of 77078221 is about 425.5760971657.

The spelling of 77078221 in words is "seventy-seven million, seventy-eight thousand, two hundred twenty-one".