21494929 has 2 divisors, whose sum is σ = 21494930. Its totient is φ = 21494928.

The previous prime is 21494917. The next prime is 21494959. The reversal of 21494929 is 92949412.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12780625 + 8714304 = 3575^2 + 2952^2 .

It is a cyclic number.

It is not a de Polignac number, because 21494929 - 2¹¹ = 21492881 is a prime.

It is a super-3 number, since 3×21494929³ (a number of 23 digits) contains 333 as substring.

It is an alternating number because its digits alternate between even and odd.

It is a zygodrome in base 3.

It is a junction number, because it is equal to n+sod(n) for n = 21494891 and 21494900.

It is not a weakly prime, because it can be changed into another prime (21494959) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10747464 + 10747465.

It is an arithmetic number, because the mean of its divisors is an integer number (10747465).

Almost surely, 2^21494929 is an apocalyptic number.

It is an amenable number.

21494929 is a deficient number, since it is larger than the sum of its proper divisors (1).

21494929 is an equidigital number, since it uses as much as digits as its factorization.

21494929 is an evil number, because the sum of its binary digits is even.

The product of its digits is 46656, while the sum is 40.

The square root of 21494929 is about 4636.2623955078. The cubic root of 21494929 is about 278.0430251025.

The spelling of 21494929 in words is "twenty-one million, four hundred ninety-four thousand, nine hundred twenty-nine".