21264017 has 2 divisors, whose sum is σ = 21264018. Its totient is φ = 21264016.

The previous prime is 21263993. The next prime is 21264031. The reversal of 21264017 is 71046212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17106496 + 4157521 = 4136^2 + 2039^2 .

It is a cyclic number.

It is not a de Polignac number, because 21264017 - 2⁸ = 21263761 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21263983 and 21264001.

It is not a weakly prime, because it can be changed into another prime (21264037) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10632008 + 10632009.

It is an arithmetic number, because the mean of its divisors is an integer number (10632009).

Almost surely, 2^21264017 is an apocalyptic number.

It is an amenable number.

21264017 is a deficient number, since it is larger than the sum of its proper divisors (1).

21264017 is an equidigital number, since it uses as much as digits as its factorization.

21264017 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 672, while the sum is 23.

The square root of 21264017 is about 4611.2923351269. The cubic root of 21264017 is about 277.0438009341.

The spelling of 21264017 in words is "twenty-one million, two hundred sixty-four thousand, seventeen".