21229693 has 2 divisors, whose sum is σ = 21229694. Its totient is φ = 21229692.

The previous prime is 21229679. The next prime is 21229709. The reversal of 21229693 is 39692212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11002489 + 10227204 = 3317^2 + 3198^2 .

It is a cyclic number.

It is not a de Polignac number, because 21229693 - 2⁵ = 21229661 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21229633) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10614846 + 10614847.

It is an arithmetic number, because the mean of its divisors is an integer number (10614847).

Almost surely, 2^21229693 is an apocalyptic number.

It is an amenable number.

21229693 is a deficient number, since it is larger than the sum of its proper divisors (1).

21229693 is an equidigital number, since it uses as much as digits as its factorization.

21229693 is an evil number, because the sum of its binary digits is even.

The product of its digits is 11664, while the sum is 34.

The square root of 21229693 is about 4607.5690987765. The cubic root of 21229693 is about 276.8946542548.

The spelling of 21229693 in words is "twenty-one million, two hundred twenty-nine thousand, six hundred ninety-three".