20723563 has 4 divisors (see below), whose sum is σ = 23684080. Its totient is φ = 17763048.

The previous prime is 20723557. The next prime is 20723567. The reversal of 20723563 is 36532702.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20723563 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20723567) 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, 1480248 + ... + 1480261.

It is an arithmetic number, because the mean of its divisors is an integer number (5921020).

Almost surely, 2^20723563 is an apocalyptic number.

20723563 is a deficient number, since it is larger than the sum of its proper divisors (2960517).

20723563 is an equidigital number, since it uses as much as digits as its factorization.

20723563 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2960516.

The product of its (nonzero) digits is 7560, while the sum is 28.

The square root of 20723563 is about 4552.3140269538. The cubic root of 20723563 is about 274.6764812595.

The spelling of 20723563 in words is "twenty million, seven hundred twenty-three thousand, five hundred sixty-three".