20164729 has 4 divisors (see below), whose sum is σ = 21715876. Its totient is φ = 18613584.

The previous prime is 20164649. The next prime is 20164733. The reversal of 20164729 is 92746102.

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

It can be written as a sum of positive squares in 2 ways, for example, as 12766329 + 7398400 = 3573^2 + 2720^2 .

It is a cyclic number.

It is not a de Polignac number, because 20164729 - 2¹⁹ = 19640441 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20164729.

It is not an unprimeable number, because it can be changed into a prime (20164429) 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 3 ways as a sum of consecutive naturals, for example, 775554 + ... + 775579.

It is an arithmetic number, because the mean of its divisors is an integer number (5428969).

Almost surely, 2^20164729 is an apocalyptic number.

It is an amenable number.

20164729 is a deficient number, since it is larger than the sum of its proper divisors (1551147).

20164729 is a wasteful number, since it uses less digits than its factorization.

20164729 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1551146.

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

The square root of 20164729 is about 4490.5154492552. The cubic root of 20164729 is about 272.1849637625.

It can be divided in two parts, 20164 and 729, that multiplied together give a square (14699556 = 3834²).

The spelling of 20164729 in words is "twenty million, one hundred sixty-four thousand, seven hundred twenty-nine".