77527421 has 2 divisors, whose sum is σ = 77527422. Its totient is φ = 77527420.

The previous prime is 77527381. The next prime is 77527447. The reversal of 77527421 is 12472577.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 77246521 + 280900 = 8789^2 + 530^2 .

It is a cyclic number.

It is not a de Polignac number, because 77527421 - 2¹⁸ = 77265277 is a prime.

It is a super-2 number, since 2×77527421² = 12021002013822482, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (77527481) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38763710 + 38763711.

It is an arithmetic number, because the mean of its divisors is an integer number (38763711).

Almost surely, 2^77527421 is an apocalyptic number.

It is an amenable number.

77527421 is a deficient number, since it is larger than the sum of its proper divisors (1).

77527421 is an equidigital number, since it uses as much as digits as its factorization.

77527421 is an evil number, because the sum of its binary digits is even.

The product of its digits is 27440, while the sum is 35.

The square root of 77527421 is about 8804.9657012393. The cubic root of 77527421 is about 426.4012269740.

Adding to 77527421 its reverse (12472577), we get a palindrome (89999998).

The spelling of 77527421 in words is "seventy-seven million, five hundred twenty-seven thousand, four hundred twenty-one".