21067513 has 2 divisors, whose sum is σ = 21067514. Its totient is φ = 21067512.

The previous prime is 21067499. The next prime is 21067531. The reversal of 21067513 is 31576012.

Together with next prime (21067531) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18766224 + 2301289 = 4332^2 + 1517^2 .

It is a cyclic number.

It is not a de Polignac number, because 21067513 - 2¹⁷ = 20936441 is a prime.

It is not a weakly prime, because it can be changed into another prime (21067583) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10533756 + 10533757.

It is an arithmetic number, because the mean of its divisors is an integer number (10533757).

Almost surely, 2^21067513 is an apocalyptic number.

It is an amenable number.

21067513 is a deficient number, since it is larger than the sum of its proper divisors (1).

21067513 is an equidigital number, since it uses as much as digits as its factorization.

21067513 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1260, while the sum is 25.

The square root of 21067513 is about 4589.9360561995. The cubic root of 21067513 is about 276.1877573166.

The spelling of 21067513 in words is "twenty-one million, sixty-seven thousand, five hundred thirteen".