20664429 has 4 divisors (see below), whose sum is σ = 27552576. Its totient is φ = 13776284.

The previous prime is 20664409. The next prime is 20664431. The reversal of 20664429 is 92446602.

It is a happy number.

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 20664429 - 2¹¹ = 20662381 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20664429.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20664409) 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, 3444069 + ... + 3444074.

It is an arithmetic number, because the mean of its divisors is an integer number (6888144).

Almost surely, 2^20664429 is an apocalyptic number.

It is an amenable number.

20664429 is a deficient number, since it is larger than the sum of its proper divisors (6888147).

20664429 is an equidigital number, since it uses as much as digits as its factorization.

20664429 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6888146.

The product of its (nonzero) digits is 20736, while the sum is 33.

The square root of 20664429 is about 4545.8144484790. The cubic root of 20664429 is about 274.4149722881.

The spelling of 20664429 in words is "twenty million, six hundred sixty-four thousand, four hundred twenty-nine".