77244421 has 2 divisors, whose sum is σ = 77244422. Its totient is φ = 77244420.

The previous prime is 77244389. The next prime is 77244457. The reversal of 77244421 is 12444277.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 77193796 + 50625 = 8786^2 + 225^2 .

It is a cyclic number.

It is not a de Polignac number, because 77244421 - 2⁵ = 77244389 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (77244491) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38622210 + 38622211.

It is an arithmetic number, because the mean of its divisors is an integer number (38622211).

Almost surely, 2^77244421 is an apocalyptic number.

It is an amenable number.

77244421 is a deficient number, since it is larger than the sum of its proper divisors (1).

77244421 is an equidigital number, since it uses as much as digits as its factorization.

77244421 is an evil number, because the sum of its binary digits is even.

The product of its digits is 12544, while the sum is 31.

The square root of 77244421 is about 8788.8805316718. The cubic root of 77244421 is about 425.8817605533.

Adding to 77244421 its reverse (12444277), we get a palindrome (89688698).

The spelling of 77244421 in words is "seventy-seven million, two hundred forty-four thousand, four hundred twenty-one".