77544212221 has 8 divisors (see below), whose sum is σ = 88626804480. Its totient is φ = 66462831888.

The previous prime is 77544212191. The next prime is 77544212227. The reversal of 77544212221 is 12221244577.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 77544212221 - 2⁵ = 77544212189 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 (77544212227) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 161461 + ... + 425626.

It is an arithmetic number, because the mean of its divisors is an integer number (11078350560).

Almost surely, 2^77544212221 is an apocalyptic number.

It is an amenable number.

77544212221 is a deficient number, since it is larger than the sum of its proper divisors (11082592259).

77544212221 is a wasteful number, since it uses less digits than its factorization.

77544212221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 605963.

The product of its digits is 62720, while the sum is 37.

Adding to 77544212221 its reverse (12221244577), we get a palindrome (89765456798).

The spelling of 77544212221 in words is "seventy-seven billion, five hundred forty-four million, two hundred twelve thousand, two hundred twenty-one".