20739823 has 8 divisors (see below), whose sum is σ = 22444016. Its totient is φ = 19051200.

The previous prime is 20739799. The next prime is 20739839. The reversal of 20739823 is 32893702.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20739823 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20739853) 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, 1038 + ... + 6523.

It is an arithmetic number, because the mean of its divisors is an integer number (2805502).

Almost surely, 2^20739823 is an apocalyptic number.

20739823 is a deficient number, since it is larger than the sum of its proper divisors (1704193).

20739823 is a wasteful number, since it uses less digits than its factorization.

20739823 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7785.

The product of its (nonzero) digits is 18144, while the sum is 34.

The square root of 20739823 is about 4554.0995816956. The cubic root of 20739823 is about 274.7483008271.

The spelling of 20739823 in words is "twenty million, seven hundred thirty-nine thousand, eight hundred twenty-three".