77433221 has 2 divisors, whose sum is σ = 77433222. Its totient is φ = 77433220.

The previous prime is 77433211. The next prime is 77433233. The reversal of 77433221 is 12233477.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 72420100 + 5013121 = 8510^2 + 2239^2 .

It is an emirp because it is prime and its reverse (12233477) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 77433221 - 2¹⁴ = 77416837 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a nialpdrome in base 10.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (77433211) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38716610 + 38716611.

It is an arithmetic number, because the mean of its divisors is an integer number (38716611).

Almost surely, 2^77433221 is an apocalyptic number.

It is an amenable number.

77433221 is a deficient number, since it is larger than the sum of its proper divisors (1).

77433221 is an equidigital number, since it uses as much as digits as its factorization.

77433221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 7056, while the sum is 29.

The square root of 77433221 is about 8799.6148211158. The cubic root of 77433221 is about 426.2284568135.

Adding to 77433221 its reverse (12233477), we get a palindrome (89666698).

The spelling of 77433221 in words is "seventy-seven million, four hundred thirty-three thousand, two hundred twenty-one".