20723146 has 16 divisors (see below), whose sum is σ = 31881600. Its totient is φ = 10097920.

The previous prime is 20723137. The next prime is 20723173. The reversal of 20723146 is 64132702.

It is a self number, because there is not a number n which added to its sum of digits gives 20723146.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 41961 + ... + 42451.

It is an arithmetic number, because the mean of its divisors is an integer number (1992600).

Almost surely, 2^20723146 is an apocalyptic number.

20723146 is a deficient number, since it is larger than the sum of its proper divisors (11158454).

20723146 is a wasteful number, since it uses less digits than its factorization.

20723146 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 989.

The product of its (nonzero) digits is 2016, while the sum is 25.

The square root of 20723146 is about 4552.2682258408. The cubic root of 20723146 is about 274.6746388984.

Adding to 20723146 its reverse (64132702), we get a palindrome (84855848).

The spelling of 20723146 in words is "twenty million, seven hundred twenty-three thousand, one hundred forty-six".