20919023 has 4 divisors (see below), whose sum is σ = 21484440. Its totient is φ = 20353608.

The previous prime is 20919011. The next prime is 20919037. The reversal of 20919023 is 32091902.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 32091902 = 2 ⋅16045951.

It is a cyclic number.

It is not a de Polignac number, because 20919023 - 2⁸ = 20918767 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20918983 and 20919001.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20919623) 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 3 ways as a sum of consecutive naturals, for example, 282653 + ... + 282726.

It is an arithmetic number, because the mean of its divisors is an integer number (5371110).

Almost surely, 2^20919023 is an apocalyptic number.

20919023 is a deficient number, since it is larger than the sum of its proper divisors (565417).

20919023 is an equidigital number, since it uses as much as digits as its factorization.

20919023 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 565416.

The product of its (nonzero) digits is 972, while the sum is 26.

The square root of 20919023 is about 4573.7318460968. The cubic root of 20919023 is about 275.5373427510.

The spelling of 20919023 in words is "twenty million, nine hundred nineteen thousand, twenty-three".