20729146 has 4 divisors (see below), whose sum is σ = 31093722. Its totient is φ = 10364572.

The previous prime is 20729131. The next prime is 20729179. The reversal of 20729146 is 64192702.

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

It can be written as a sum of positive squares in only one way, i.e., 17347225 + 3381921 = 4165^2 + 1839^2 .

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

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 as a sum of consecutive naturals, namely, 5182285 + ... + 5182288.

Almost surely, 2^20729146 is an apocalyptic number.

20729146 is a deficient number, since it is larger than the sum of its proper divisors (10364576).

20729146 is a wasteful number, since it uses less digits than its factorization.

20729146 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10364575.

The product of its (nonzero) digits is 6048, while the sum is 31.

The square root of 20729146 is about 4552.9271902810. The cubic root of 20729146 is about 274.7011453115.

The spelling of 20729146 in words is "twenty million, seven hundred twenty-nine thousand, one hundred forty-six".