20780823 has 16 divisors (see below), whose sum is σ = 32265216. Its totient is φ = 11650080.

The previous prime is 20780807. The next prime is 20780827. The reversal of 20780823 is 32808702.

It is not a de Polignac number, because 20780823 - 2⁴ = 20780807 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20780827) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8223 + ... + 10448.

It is an arithmetic number, because the mean of its divisors is an integer number (2016576).

Almost surely, 2^20780823 is an apocalyptic number.

20780823 is a deficient number, since it is larger than the sum of its proper divisors (11484393).

20780823 is a wasteful number, since it uses less digits than its factorization.

20780823 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18734.

The product of its (nonzero) digits is 5376, while the sum is 30.

The square root of 20780823 is about 4558.5987978764. The cubic root of 20780823 is about 274.9292291717.

The spelling of 20780823 in words is "twenty million, seven hundred eighty thousand, eight hundred twenty-three".