20730309 has 4 divisors (see below), whose sum is σ = 27640416. Its totient is φ = 13820204.

The previous prime is 20730277. The next prime is 20730313. The reversal of 20730309 is 90303702.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 20730309 - 2⁵ = 20730277 is a prime.

It is a super-2 number, since 2×20730309² = 859491422470962, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20730109) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3455049 + ... + 3455054.

It is an arithmetic number, because the mean of its divisors is an integer number (6910104).

Almost surely, 2^20730309 is an apocalyptic number.

It is an amenable number.

20730309 is a deficient number, since it is larger than the sum of its proper divisors (6910107).

20730309 is an equidigital number, since it uses as much as digits as its factorization.

20730309 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6910106.

The product of its (nonzero) digits is 1134, while the sum is 24.

The square root of 20730309 is about 4553.0549085202. The cubic root of 20730309 is about 274.7062825461.

The spelling of 20730309 in words is "twenty million, seven hundred thirty thousand, three hundred nine".