21067537 has 2 divisors, whose sum is σ = 21067538. Its totient is φ = 21067536.

The previous prime is 21067531. The next prime is 21067567. The reversal of 21067537 is 73576012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12680721 + 8386816 = 3561^2 + 2896^2 .

It is a cyclic number.

It is not a de Polignac number, because 21067537 - 2¹¹ = 21065489 is a prime.

It is a super-2 number, since 2×21067537² = 887682230492738, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21067499 and 21067508.

It is not a weakly prime, because it can be changed into another prime (21067531) 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, 10533768 + 10533769.

It is an arithmetic number, because the mean of its divisors is an integer number (10533769).

Almost surely, 2^21067537 is an apocalyptic number.

It is an amenable number.

21067537 is a deficient number, since it is larger than the sum of its proper divisors (1).

21067537 is an equidigital number, since it uses as much as digits as its factorization.

21067537 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8820, while the sum is 31.

The square root of 21067537 is about 4589.9386706142. The cubic root of 21067537 is about 276.1878621938.

The spelling of 21067537 in words is "twenty-one million, sixty-seven thousand, five hundred thirty-seven".