77544421 has 2 divisors, whose sum is σ = 77544422. Its totient is φ = 77544420.

The previous prime is 77544413. The next prime is 77544433. The reversal of 77544421 is 12444577.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 48233025 + 29311396 = 6945^2 + 5414^2 .

It is a cyclic number.

It is not a de Polignac number, because 77544421 - 2³ = 77544413 is a prime.

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 (77545421) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38772210 + 38772211.

It is an arithmetic number, because the mean of its divisors is an integer number (38772211).

Almost surely, 2^77544421 is an apocalyptic number.

It is an amenable number.

77544421 is a deficient number, since it is larger than the sum of its proper divisors (1).

77544421 is an equidigital number, since it uses as much as digits as its factorization.

77544421 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 31360, while the sum is 34.

The square root of 77544421 is about 8805.9310126755. The cubic root of 77544421 is about 426.4323913930.

Adding to 77544421 its reverse (12444577), we get a palindrome (89988998).

The spelling of 77544421 in words is "seventy-seven million, five hundred forty-four thousand, four hundred twenty-one".