21021703 has 2 divisors, whose sum is σ = 21021704. Its totient is φ = 21021702.

The previous prime is 21021697. The next prime is 21021709. The reversal of 21021703 is 30712012.

It is a happy number.

It is a balanced prime because it is at equal distance from previous prime (21021697) and next prime (21021709).

It is a cyclic number.

It is not a de Polignac number, because 21021703 - 2¹³ = 21013511 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21021709) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10510851 + 10510852.

It is an arithmetic number, because the mean of its divisors is an integer number (10510852).

Almost surely, 2^21021703 is an apocalyptic number.

21021703 is a deficient number, since it is larger than the sum of its proper divisors (1).

21021703 is an equidigital number, since it uses as much as digits as its factorization.

21021703 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 84, while the sum is 16.

The square root of 21021703 is about 4584.9430748920. The cubic root of 21021703 is about 275.9874276637.

Adding to 21021703 its reverse (30712012), we get a palindrome (51733715).

The spelling of 21021703 in words is "twenty-one million, twenty-one thousand, seven hundred three".