20309919 has 8 divisors (see below), whose sum is σ = 30948480. Its totient is φ = 11605656.

The previous prime is 20309903. The next prime is 20309921. The reversal of 20309919 is 91990302.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 20309919 - 2⁴ = 20309903 is a prime.

It is a super-2 number, since 2×20309919² = 824985619573122, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 20309919.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20309959) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 483549 + ... + 483590.

It is an arithmetic number, because the mean of its divisors is an integer number (3868560).

Almost surely, 2^20309919 is an apocalyptic number.

20309919 is a deficient number, since it is larger than the sum of its proper divisors (10638561).

20309919 is an equidigital number, since it uses as much as digits as its factorization.

20309919 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 967149.

The product of its (nonzero) digits is 4374, while the sum is 33.

The square root of 20309919 is about 4506.6527489923. The cubic root of 20309919 is about 272.8366638244.

The spelling of 20309919 in words is "twenty million, three hundred nine thousand, nine hundred nineteen".