77743621 has 2 divisors, whose sum is σ = 77743622. Its totient is φ = 77743620.

The previous prime is 77743619. The next prime is 77743643. The reversal of 77743621 is 12634777.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 49547521 + 28196100 = 7039^2 + 5310^2 .

It is an emirp because it is prime and its reverse (12634777) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 77743621 - 2¹ = 77743619 is a prime.

Together with 77743619, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (77743021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38871810 + 38871811.

It is an arithmetic number, because the mean of its divisors is an integer number (38871811).

Almost surely, 2^77743621 is an apocalyptic number.

It is an amenable number.

77743621 is a deficient number, since it is larger than the sum of its proper divisors (1).

77743621 is an equidigital number, since it uses as much as digits as its factorization.

77743621 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 49392, while the sum is 37.

The square root of 77743621 is about 8817.2343169500. The cubic root of 77743621 is about 426.7972261446.

The spelling of 77743621 in words is "seventy-seven million, seven hundred forty-three thousand, six hundred twenty-one".