20140643 has 2 divisors, whose sum is σ = 20140644. Its totient is φ = 20140642.

The previous prime is 20140639. The next prime is 20140657. The reversal of 20140643 is 34604102.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20140643 - 2² = 20140639 is a prime.

It is not a weakly prime, because it can be changed into another prime (20140613) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10070321 + 10070322.

It is an arithmetic number, because the mean of its divisors is an integer number (10070322).

Almost surely, 2^20140643 is an apocalyptic number.

20140643 is a deficient number, since it is larger than the sum of its proper divisors (1).

20140643 is an equidigital number, since it uses as much as digits as its factorization.

20140643 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 576, while the sum is 20.

The square root of 20140643 is about 4487.8327731768. The cubic root of 20140643 is about 272.0765490646.

Adding to 20140643 its reverse (34604102), we get a palindrome (54744745).

The spelling of 20140643 in words is "twenty million, one hundred forty thousand, six hundred forty-three".