20723617 has 2 divisors, whose sum is σ = 20723618. Its totient is φ = 20723616.

The previous prime is 20723609. The next prime is 20723627. The reversal of 20723617 is 71632702.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12680721 + 8042896 = 3561^2 + 2836^2 .

It is a cyclic number.

It is not a de Polignac number, because 20723617 - 2³ = 20723609 is a prime.

It is not a weakly prime, because it can be changed into another prime (20723627) 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, 10361808 + 10361809.

It is an arithmetic number, because the mean of its divisors is an integer number (10361809).

Almost surely, 2^20723617 is an apocalyptic number.

It is an amenable number.

20723617 is a deficient number, since it is larger than the sum of its proper divisors (1).

20723617 is an equidigital number, since it uses as much as digits as its factorization.

20723617 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3528, while the sum is 28.

The square root of 20723617 is about 4552.3199579994. The cubic root of 20723617 is about 274.6767198368.

The spelling of 20723617 in words is "twenty million, seven hundred twenty-three thousand, six hundred seventeen".