77283221 has 2 divisors, whose sum is σ = 77283222. Its totient is φ = 77283220.

The previous prime is 77283179. The next prime is 77283223. The reversal of 77283221 is 12238277.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 47416996 + 29866225 = 6886^2 + 5465^2 .

It is a cyclic number.

It is not a de Polignac number, because 77283221 - 2¹⁰ = 77282197 is a prime.

It is a Sophie Germain prime.

Together with 77283223, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (77283223) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38641610 + 38641611.

It is an arithmetic number, because the mean of its divisors is an integer number (38641611).

Almost surely, 2^77283221 is an apocalyptic number.

It is an amenable number.

77283221 is a deficient number, since it is larger than the sum of its proper divisors (1).

77283221 is an equidigital number, since it uses as much as digits as its factorization.

77283221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 9408, while the sum is 32.

The square root of 77283221 is about 8791.0875891439. The cubic root of 77283221 is about 425.9530556542.

The spelling of 77283221 in words is "seventy-seven million, two hundred eighty-three thousand, two hundred twenty-one".