77768221 has 8 divisors (see below), whose sum is σ = 82877184. Its totient is φ = 72803280.

The previous prime is 77768203. The next prime is 77768231. The reversal of 77768221 is 12286777.

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

It is not a de Polignac number, because 77768221 - 2¹³ = 77760029 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 (77768231) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 34890 + ... + 37051.

It is an arithmetic number, because the mean of its divisors is an integer number (10359648).

Almost surely, 2^77768221 is an apocalyptic number.

It is an amenable number.

77768221 is a deficient number, since it is larger than the sum of its proper divisors (5108963).

77768221 is a wasteful number, since it uses less digits than its factorization.

77768221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 72011.

The product of its digits is 65856, while the sum is 40.

The square root of 77768221 is about 8818.6292018658. The cubic root of 77768221 is about 426.8422377885.

The spelling of 77768221 in words is "seventy-seven million, seven hundred sixty-eight thousand, two hundred twenty-one".