20603993 has 2 divisors, whose sum is σ = 20603994. Its totient is φ = 20603992.

The previous prime is 20603977. The next prime is 20604011. The reversal of 20603993 is 39930602.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20403289 + 200704 = 4517^2 + 448^2 .

It is a cyclic number.

It is not a de Polignac number, because 20603993 - 2⁴ = 20603977 is a prime.

It is not a weakly prime, because it can be changed into another prime (20603893) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10301996 + 10301997.

It is an arithmetic number, because the mean of its divisors is an integer number (10301997).

Almost surely, 2^20603993 is an apocalyptic number.

It is an amenable number.

20603993 is a deficient number, since it is larger than the sum of its proper divisors (1).

20603993 is an equidigital number, since it uses as much as digits as its factorization.

20603993 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8748, while the sum is 32.

The square root of 20603993 is about 4539.1621473572. The cubic root of 20603993 is about 274.1471894631.

The spelling of 20603993 in words is "twenty million, six hundred three thousand, nine hundred ninety-three".