20756243 has 2 divisors, whose sum is σ = 20756244. Its totient is φ = 20756242.

The previous prime is 20756237. The next prime is 20756261. The reversal of 20756243 is 34265702.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20756243 is a prime.

It is not a weakly prime, because it can be changed into another prime (20756213) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10378121 + 10378122.

It is an arithmetic number, because the mean of its divisors is an integer number (10378122).

Almost surely, 2^20756243 is an apocalyptic number.

20756243 is a deficient number, since it is larger than the sum of its proper divisors (1).

20756243 is an equidigital number, since it uses as much as digits as its factorization.

20756243 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 10080, while the sum is 29.

The square root of 20756243 is about 4555.9019963120. The cubic root of 20756243 is about 274.8207890230.

The spelling of 20756243 in words is "twenty million, seven hundred fifty-six thousand, two hundred forty-three".