77007421 has 2 divisors, whose sum is σ = 77007422. Its totient is φ = 77007420.

The previous prime is 77007419. The next prime is 77007431. The reversal of 77007421 is 12470077.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 72012196 + 4995225 = 8486^2 + 2235^2 .

It is a cyclic number.

It is not a de Polignac number, because 77007421 - 2¹ = 77007419 is a prime.

Together with 77007419, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 77007421.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (77007431) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38503710 + 38503711.

It is an arithmetic number, because the mean of its divisors is an integer number (38503711).

Almost surely, 2^77007421 is an apocalyptic number.

It is an amenable number.

77007421 is a deficient number, since it is larger than the sum of its proper divisors (1).

77007421 is an equidigital number, since it uses as much as digits as its factorization.

77007421 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2744, while the sum is 28.

The square root of 77007421 is about 8775.3872279233. The cubic root of 77007421 is about 425.4457533084.

Adding to 77007421 its reverse (12470077), we get a palindrome (89477498).

The spelling of 77007421 in words is "seventy-seven million, seven thousand, four hundred twenty-one".