20742643 has 2 divisors, whose sum is σ = 20742644. Its totient is φ = 20742642.

The previous prime is 20742637. The next prime is 20742649. The reversal of 20742643 is 34624702.

It is a balanced prime because it is at equal distance from previous prime (20742637) and next prime (20742649).

It is a cyclic number.

It is not a de Polignac number, because 20742643 - 2¹³ = 20734451 is a prime.

It is not a weakly prime, because it can be changed into another prime (20742649) 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, 10371321 + 10371322.

It is an arithmetic number, because the mean of its divisors is an integer number (10371322).

Almost surely, 2^20742643 is an apocalyptic number.

20742643 is a deficient number, since it is larger than the sum of its proper divisors (1).

20742643 is an equidigital number, since it uses as much as digits as its factorization.

20742643 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8064, while the sum is 28.

The square root of 20742643 is about 4554.4091823199. The cubic root of 20742643 is about 274.7607527993.

The spelling of 20742643 in words is "twenty million, seven hundred forty-two thousand, six hundred forty-three".