20720633 has 2 divisors, whose sum is σ = 20720634. Its totient is φ = 20720632.

The previous prime is 20720611. The next prime is 20720653. The reversal of 20720633 is 33602702.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 10936249 + 9784384 = 3307^2 + 3128^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20720633 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20720599 and 20720608.

It is not a weakly prime, because it can be changed into another prime (20720653) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10360316 + 10360317.

It is an arithmetic number, because the mean of its divisors is an integer number (10360317).

Almost surely, 2^20720633 is an apocalyptic number.

It is an amenable number.

20720633 is a deficient number, since it is larger than the sum of its proper divisors (1).

20720633 is an equidigital number, since it uses as much as digits as its factorization.

20720633 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1512, while the sum is 23.

The square root of 20720633 is about 4551.9922012235. The cubic root of 20720633 is about 274.6635356088.

The spelling of 20720633 in words is "twenty million, seven hundred twenty thousand, six hundred thirty-three".