20007729 has 45 divisors (see below), whose sum is σ = 35264361. Its totient is φ = 11271960.

The previous prime is 20007721. The next prime is 20007737. The reversal of 20007729 is 92770002.

The square root of 20007729 is 4473.

It is a perfect power (a square), and thus also a powerful number.

It is an interprime number because it is at equal distance from previous prime (20007721) and next prime (20007737).

It is not a de Polignac number, because 20007729 - 2³ = 20007721 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (20007721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 44 ways as a sum of consecutive naturals, for example, 281764 + ... + 281834.

Almost surely, 2^20007729 is an apocalyptic number.

20007729 is the 4473-rd square number.

20007729 is the 2237-th centered octagonal number.

It is an amenable number.

20007729 is a deficient number, since it is larger than the sum of its proper divisors (15256632).

20007729 is an frugal number, since it uses more digits than its factorization.

20007729 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 168 (or 81 counting only the distinct ones).

The product of its (nonzero) digits is 1764, while the sum is 27.

The cubic root of 20007729 is about 271.4767233792.

Multiplying 20007729 by its product of nonzero digits (1764), we get a square (35293633956 = 187866²).

It can be divided in two parts, 20007 and 729, that added together give a 4-th power (20736 = 12⁴).

The spelling of 20007729 in words is "twenty million, seven thousand, seven hundred twenty-nine".