20943749 has 2 divisors, whose sum is σ = 20943750. Its totient is φ = 20943748.

The previous prime is 20943737. The next prime is 20943763. The reversal of 20943749 is 94734902.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18335524 + 2608225 = 4282^2 + 1615^2 .

It is a cyclic number.

It is not a de Polignac number, because 20943749 - 2⁸ = 20943493 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20943799) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10471874 + 10471875.

It is an arithmetic number, because the mean of its divisors is an integer number (10471875).

Almost surely, 2^20943749 is an apocalyptic number.

It is an amenable number.

20943749 is a deficient number, since it is larger than the sum of its proper divisors (1).

20943749 is an equidigital number, since it uses as much as digits as its factorization.

20943749 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 54432, while the sum is 38.

The square root of 20943749 is about 4576.4340921726. The cubic root of 20943749 is about 275.6458604677.

The spelling of 20943749 in words is "twenty million, nine hundred forty-three thousand, seven hundred forty-nine".