77373221 has 2 divisors, whose sum is σ = 77373222. Its totient is φ = 77373220.

The previous prime is 77373217. The next prime is 77373223. The reversal of 77373221 is 12237377.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 48804196 + 28569025 = 6986^2 + 5345^2 .

It is an emirp because it is prime and its reverse (12237377) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 77373221 - 2² = 77373217 is a prime.

Together with 77373223, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (77373223) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38686610 + 38686611.

It is an arithmetic number, because the mean of its divisors is an integer number (38686611).

Almost surely, 2^77373221 is an apocalyptic number.

It is an amenable number.

77373221 is a deficient number, since it is larger than the sum of its proper divisors (1).

77373221 is an equidigital number, since it uses as much as digits as its factorization.

77373221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 12348, while the sum is 32.

The square root of 77373221 is about 8796.2049203051. The cubic root of 77373221 is about 426.1183390661.

The spelling of 77373221 in words is "seventy-seven million, three hundred seventy-three thousand, two hundred twenty-one".