20531783 has 2 divisors, whose sum is σ = 20531784. Its totient is φ = 20531782.

The previous prime is 20531747. The next prime is 20531789. The reversal of 20531783 is 38713502.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20531783 - 2¹⁰ = 20530759 is a prime.

It is a super-2 number, since 2×20531783² = 843108226318178, which contains 22 as substring.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20531789) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10265891 + 10265892.

It is an arithmetic number, because the mean of its divisors is an integer number (10265892).

Almost surely, 2^20531783 is an apocalyptic number.

20531783 is a deficient number, since it is larger than the sum of its proper divisors (1).

20531783 is an equidigital number, since it uses as much as digits as its factorization.

20531783 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5040, while the sum is 29.

The square root of 20531783 is about 4531.2010549081. The cubic root of 20531783 is about 273.8265503202.

The spelling of 20531783 in words is "twenty million, five hundred thirty-one thousand, seven hundred eighty-three".