21610837 has 2 divisors, whose sum is σ = 21610838. Its totient is φ = 21610836.

The previous prime is 21610807. The next prime is 21610861. The reversal of 21610837 is 73801612.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17901361 + 3709476 = 4231^2 + 1926^2 .

It is a cyclic number.

It is not a de Polignac number, because 21610837 - 2²³ = 13222229 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 (21610807) 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, 10805418 + 10805419.

It is an arithmetic number, because the mean of its divisors is an integer number (10805419).

Almost surely, 2^21610837 is an apocalyptic number.

It is an amenable number.

21610837 is a deficient number, since it is larger than the sum of its proper divisors (1).

21610837 is an equidigital number, since it uses as much as digits as its factorization.

21610837 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2016, while the sum is 28.

The square root of 21610837 is about 4648.7457448219. The cubic root of 21610837 is about 278.5418971356.

The spelling of 21610837 in words is "twenty-one million, six hundred ten thousand, eight hundred thirty-seven".