20631973 has 2 divisors, whose sum is σ = 20631974. Its totient is φ = 20631972.

The previous prime is 20631971. The next prime is 20631983. The reversal of 20631973 is 37913602.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20629764 + 2209 = 4542^2 + 47^2 .

It is a cyclic number.

It is not a de Polignac number, because 20631973 - 2¹ = 20631971 is a prime.

Together with 20631971, 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 (20631971) 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, 10315986 + 10315987.

It is an arithmetic number, because the mean of its divisors is an integer number (10315987).

Almost surely, 2^20631973 is an apocalyptic number.

It is an amenable number.

20631973 is a deficient number, since it is larger than the sum of its proper divisors (1).

20631973 is an equidigital number, since it uses as much as digits as its factorization.

20631973 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 20631973 is about 4542.2431683035. The cubic root of 20631973 is about 274.2712296393.

The spelling of 20631973 in words is "twenty million, six hundred thirty-one thousand, nine hundred seventy-three".