21392017 has 2 divisors, whose sum is σ = 21392018. Its totient is φ = 21392016.

The previous prime is 21392011. The next prime is 21392023. The reversal of 21392017 is 71029312.

It is a balanced prime because it is at equal distance from previous prime (21392011) and next prime (21392023).

It can be written as a sum of positive squares in only one way, i.e., 20439441 + 952576 = 4521^2 + 976^2 .

It is a cyclic number.

It is not a de Polignac number, because 21392017 - 2⁷ = 21391889 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21391982 and 21392000.

It is not a weakly prime, because it can be changed into another prime (21392011) 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, 10696008 + 10696009.

It is an arithmetic number, because the mean of its divisors is an integer number (10696009).

Almost surely, 2^21392017 is an apocalyptic number.

It is an amenable number.

21392017 is a deficient number, since it is larger than the sum of its proper divisors (1).

21392017 is an equidigital number, since it uses as much as digits as its factorization.

21392017 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 756, while the sum is 25.

The square root of 21392017 is about 4625.1504840383. The cubic root of 21392017 is about 277.5985830513.

The spelling of 21392017 in words is "twenty-one million, three hundred ninety-two thousand, seventeen".