21456077 has 2 divisors, whose sum is σ = 21456078. Its totient is φ = 21456076.

The previous prime is 21456067. The next prime is 21456089. The reversal of 21456077 is 77065412.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20620681 + 835396 = 4541^2 + 914^2 .

It is a cyclic number.

It is not a de Polignac number, because 21456077 - 2⁸ = 21455821 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21456007) 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, 10728038 + 10728039.

It is an arithmetic number, because the mean of its divisors is an integer number (10728039).

Almost surely, 2^21456077 is an apocalyptic number.

It is an amenable number.

21456077 is a deficient number, since it is larger than the sum of its proper divisors (1).

21456077 is an equidigital number, since it uses as much as digits as its factorization.

21456077 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 11760, while the sum is 32.

The square root of 21456077 is about 4632.0704873739. The cubic root of 21456077 is about 277.8754035103.

The spelling of 21456077 in words is "twenty-one million, four hundred fifty-six thousand, seventy-seven".