77168221 has 4 divisors (see below), whose sum is σ = 83104252. Its totient is φ = 71232192.

The previous prime is 77168209. The next prime is 77168237. The reversal of 77168221 is 12286177.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12286177 = 2897 ⋅4241.

It can be written as a sum of positive squares in 2 ways, for example, as 23145721 + 54022500 = 4811^2 + 7350^2 .

It is a cyclic number.

It is not a de Polignac number, because 77168221 - 2⁷ = 77168093 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 (77160221) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2967996 + ... + 2968021.

It is an arithmetic number, because the mean of its divisors is an integer number (20776063).

Almost surely, 2^77168221 is an apocalyptic number.

It is an amenable number.

77168221 is a deficient number, since it is larger than the sum of its proper divisors (5936031).

77168221 is a wasteful number, since it uses less digits than its factorization.

77168221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5936030.

The product of its digits is 9408, while the sum is 34.

The square root of 77168221 is about 8784.5444389564. The cubic root of 77168221 is about 425.7416733395.

The spelling of 77168221 in words is "seventy-seven million, one hundred sixty-eight thousand, two hundred twenty-one".