20421669 has 8 divisors (see below), whose sum is σ = 27964960. Its totient is φ = 13246416.

The previous prime is 20421647. The next prime is 20421691. The reversal of 20421669 is 96612402.

It is an interprime number because it is at equal distance from previous prime (20421647) and next prime (20421691).

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 20421669 - 2⁸ = 20421413 is a prime.

It is a super-2 number, since 2×20421669² = 834089129491122, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20421629) 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 7 ways as a sum of consecutive naturals, for example, 91879 + ... + 92100.

It is an arithmetic number, because the mean of its divisors is an integer number (3495620).

Almost surely, 2^20421669 is an apocalyptic number.

It is an amenable number.

20421669 is a deficient number, since it is larger than the sum of its proper divisors (7543291).

20421669 is a wasteful number, since it uses less digits than its factorization.

20421669 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 184019.

The product of its (nonzero) digits is 5184, while the sum is 30.

The square root of 20421669 is about 4519.0340782074. The cubic root of 20421669 is about 273.3361528892.

The spelling of 20421669 in words is "twenty million, four hundred twenty-one thousand, six hundred sixty-nine".