20723505 has 16 divisors (see below), whose sum is σ = 36172224. Its totient is φ = 10047680.

The previous prime is 20723503. The next prime is 20723513. The reversal of 20723505 is 50532702.

It is not a de Polignac number, because 20723505 - 2¹ = 20723503 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20723503) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 62634 + ... + 62963.

It is an arithmetic number, because the mean of its divisors is an integer number (2260764).

Almost surely, 2^20723505 is an apocalyptic number.

It is an amenable number.

20723505 is a deficient number, since it is larger than the sum of its proper divisors (15448719).

20723505 is a wasteful number, since it uses less digits than its factorization.

20723505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 125616.

The product of its (nonzero) digits is 2100, while the sum is 24.

The square root of 20723505 is about 4552.3076565628. The cubic root of 20723505 is about 274.6762250093.

The spelling of 20723505 in words is "twenty million, seven hundred twenty-three thousand, five hundred five".