20531983 has 2 divisors, whose sum is σ = 20531984. Its totient is φ = 20531982.

The previous prime is 20531981. The next prime is 20531999. The reversal of 20531983 is 38913502.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20531983 - 2¹ = 20531981 is a prime.

Together with 20531981, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20531981) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10265991 + 10265992.

It is an arithmetic number, because the mean of its divisors is an integer number (10265992).

Almost surely, 2^20531983 is an apocalyptic number.

20531983 is a deficient number, since it is larger than the sum of its proper divisors (1).

20531983 is an equidigital number, since it uses as much as digits as its factorization.

20531983 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6480, while the sum is 31.

The square root of 20531983 is about 4531.2231240582. The cubic root of 20531983 is about 273.8274394317.

The spelling of 20531983 in words is "twenty million, five hundred thirty-one thousand, nine hundred eighty-three".