21670933 has 2 divisors, whose sum is σ = 21670934. Its totient is φ = 21670932.

The previous prime is 21670897. The next prime is 21670967. The reversal of 21670933 is 33907612.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13593969 + 8076964 = 3687^2 + 2842^2 .

It is a cyclic number.

It is not a de Polignac number, because 21670933 - 2¹³ = 21662741 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21670895 and 21670904.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21670973) 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, 10835466 + 10835467.

It is an arithmetic number, because the mean of its divisors is an integer number (10835467).

Almost surely, 2^21670933 is an apocalyptic number.

It is an amenable number.

21670933 is a deficient number, since it is larger than the sum of its proper divisors (1).

21670933 is an equidigital number, since it uses as much as digits as its factorization.

21670933 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6804, while the sum is 31.

The square root of 21670933 is about 4655.2049364126. The cubic root of 21670933 is about 278.7998504556.

The spelling of 21670933 in words is "twenty-one million, six hundred seventy thousand, nine hundred thirty-three".