21422429 has 8 divisors (see below), whose sum is σ = 24518208. Its totient is φ = 18335520.

The previous prime is 21422419. The next prime is 21422449. The reversal of 21422429 is 92422412.

It is a happy number.

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

It is not a de Polignac number, because 21422429 - 2⁴ = 21422413 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21422398 and 21422407.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21422419) 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, 4214 + ... + 7784.

It is an arithmetic number, because the mean of its divisors is an integer number (3064776).

Almost surely, 2^21422429 is an apocalyptic number.

It is an amenable number.

21422429 is a deficient number, since it is larger than the sum of its proper divisors (3095779).

21422429 is an equidigital number, since it uses as much as digits as its factorization.

21422429 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4435.

The product of its digits is 2304, while the sum is 26.

The square root of 21422429 is about 4628.4369931976. The cubic root of 21422429 is about 277.7300702720.

The spelling of 21422429 in words is "twenty-one million, four hundred twenty-two thousand, four hundred twenty-nine".