20673643 has 2 divisors, whose sum is σ = 20673644. Its totient is φ = 20673642.

The previous prime is 20673629. The next prime is 20673647. The reversal of 20673643 is 34637602.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20673643 - 2⁹ = 20673131 is a prime.

It is not a weakly prime, because it can be changed into another prime (20673647) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10336821 + 10336822.

It is an arithmetic number, because the mean of its divisors is an integer number (10336822).

Almost surely, 2^20673643 is an apocalyptic number.

20673643 is a deficient number, since it is larger than the sum of its proper divisors (1).

20673643 is an equidigital number, since it uses as much as digits as its factorization.

20673643 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 18144, while the sum is 31.

The square root of 20673643 is about 4546.8277952876. The cubic root of 20673643 is about 274.4557522494.

It can be divided in two parts, 20673 and 643, that added together give a square (21316 = 146²).

The spelling of 20673643 in words is "twenty million, six hundred seventy-three thousand, six hundred forty-three".