21061037 has 2 divisors, whose sum is σ = 21061038. Its totient is φ = 21061036.

The previous prime is 21061021. The next prime is 21061057. The reversal of 21061037 is 73016012.

It is a happy number.

It is an a-pointer prime, because the next prime (21061057) can be obtained adding 21061037 to its sum of digits (20).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21058921 + 2116 = 4589^2 + 46^2 .

It is a cyclic number.

It is not a de Polignac number, because 21061037 - 2⁴ = 21061021 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21061057) 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, 10530518 + 10530519.

It is an arithmetic number, because the mean of its divisors is an integer number (10530519).

Almost surely, 2^21061037 is an apocalyptic number.

It is an amenable number.

21061037 is a deficient number, since it is larger than the sum of its proper divisors (1).

21061037 is an equidigital number, since it uses as much as digits as its factorization.

21061037 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 252, while the sum is 20.

The square root of 21061037 is about 4589.2305455272. The cubic root of 21061037 is about 276.1594550484.

Adding to 21061037 its reverse (73016012), we get a palindrome (94077049).

The spelling of 21061037 in words is "twenty-one million, sixty-one thousand, thirty-seven".