21384673 has 2 divisors, whose sum is σ = 21384674. Its totient is φ = 21384672.

The previous prime is 21384667. The next prime is 21384679. The reversal of 21384673 is 37648312.

It is a happy number.

It is a balanced prime because it is at equal distance from previous prime (21384667) and next prime (21384679).

It can be written as a sum of positive squares in only one way, i.e., 21372129 + 12544 = 4623^2 + 112^2 .

21384673 is a truncatable prime.

It is a cyclic number.

It is not a de Polignac number, because 21384673 - 2⁹ = 21384161 is a prime.

It is not a weakly prime, because it can be changed into another prime (21384679) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10692336 + 10692337.

It is an arithmetic number, because the mean of its divisors is an integer number (10692337).

Almost surely, 2^21384673 is an apocalyptic number.

It is an amenable number.

21384673 is a deficient number, since it is larger than the sum of its proper divisors (1).

21384673 is an equidigital number, since it uses as much as digits as its factorization.

21384673 is an evil number, because the sum of its binary digits is even.

The product of its digits is 24192, while the sum is 34.

The square root of 21384673 is about 4624.3564957732. The cubic root of 21384673 is about 277.5668123627.

The spelling of 21384673 in words is "twenty-one million, three hundred eighty-four thousand, six hundred seventy-three".