77305421 has 2 divisors, whose sum is σ = 77305422. Its totient is φ = 77305420.

The previous prime is 77305391. The next prime is 77305427. The reversal of 77305421 is 12450377.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 57547396 + 19758025 = 7586^2 + 4445^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-77305421 is a prime.

It is a super-2 number, since 2×77305421² = 11952256231974482, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (77305427) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38652710 + 38652711.

It is an arithmetic number, because the mean of its divisors is an integer number (38652711).

Almost surely, 2^77305421 is an apocalyptic number.

It is an amenable number.

77305421 is a deficient number, since it is larger than the sum of its proper divisors (1).

77305421 is an equidigital number, since it uses as much as digits as its factorization.

77305421 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5880, while the sum is 29.

The square root of 77305421 is about 8792.3501408895. The cubic root of 77305421 is about 425.9938374798.

Adding to 77305421 its reverse (12450377), we get a palindrome (89755798).

The spelling of 77305421 in words is "seventy-seven million, three hundred five thousand, four hundred twenty-one".