21404983 has 2 divisors, whose sum is σ = 21404984. Its totient is φ = 21404982.

The previous prime is 21404941. The next prime is 21405047. The reversal of 21404983 is 38940412.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21404983 - 2¹⁷ = 21273911 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21404923) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10702491 + 10702492.

It is an arithmetic number, because the mean of its divisors is an integer number (10702492).

Almost surely, 2^21404983 is an apocalyptic number.

21404983 is a deficient number, since it is larger than the sum of its proper divisors (1).

21404983 is an equidigital number, since it uses as much as digits as its factorization.

21404983 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6912, while the sum is 31.

The square root of 21404983 is about 4626.5519558306. The cubic root of 21404983 is about 277.6546571820.

The spelling of 21404983 in words is "twenty-one million, four hundred four thousand, nine hundred eighty-three".