20644633 has 2 divisors, whose sum is σ = 20644634. Its totient is φ = 20644632.

The previous prime is 20644627. The next prime is 20644649. The reversal of 20644633 is 33644602.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11108889 + 9535744 = 3333^2 + 3088^2 .

It is a cyclic number.

It is not a de Polignac number, because 20644633 - 2¹⁷ = 20513561 is a prime.

It is not a weakly prime, because it can be changed into another prime (20644693) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10322316 + 10322317.

It is an arithmetic number, because the mean of its divisors is an integer number (10322317).

Almost surely, 2^20644633 is an apocalyptic number.

It is an amenable number.

20644633 is a deficient number, since it is larger than the sum of its proper divisors (1).

20644633 is an equidigital number, since it uses as much as digits as its factorization.

20644633 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 10368, while the sum is 28.

The square root of 20644633 is about 4543.6365391611. The cubic root of 20644633 is about 274.3273167587.

The spelling of 20644633 in words is "twenty million, six hundred forty-four thousand, six hundred thirty-three".