20499729 has 4 divisors (see below), whose sum is σ = 27332976. Its totient is φ = 13666484.

The previous prime is 20499697. The next prime is 20499749. The reversal of 20499729 is 92799402.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 20499729 - 2⁵ = 20499697 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20499749) 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 3 ways as a sum of consecutive naturals, for example, 3416619 + ... + 3416624.

It is an arithmetic number, because the mean of its divisors is an integer number (6833244).

Almost surely, 2^20499729 is an apocalyptic number.

It is an amenable number.

20499729 is a deficient number, since it is larger than the sum of its proper divisors (6833247).

20499729 is an equidigital number, since it uses as much as digits as its factorization.

20499729 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6833246.

The product of its (nonzero) digits is 81648, while the sum is 42.

The square root of 20499729 is about 4527.6626420262. The cubic root of 20499729 is about 273.6839777397.

The spelling of 20499729 in words is "twenty million, four hundred ninety-nine thousand, seven hundred twenty-nine".