21854429 has 8 divisors (see below), whose sum is σ = 22822560. Its totient is φ = 20900656.

The previous prime is 21854423. The next prime is 21854431. The reversal of 21854429 is 92445812.

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

It is a cyclic number.

It is not a de Polignac number, because 21854429 - 2¹² = 21850333 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21854423) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 419 + ... + 6624.

It is an arithmetic number, because the mean of its divisors is an integer number (2852820).

Almost surely, 2^21854429 is an apocalyptic number.

21854429 is a gapful number since it is divisible by the number (29) formed by its first and last digit.

It is an amenable number.

21854429 is a deficient number, since it is larger than the sum of its proper divisors (968131).

21854429 is a wasteful number, since it uses less digits than its factorization.

21854429 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7179.

The product of its digits is 23040, while the sum is 35.

The square root of 21854429 is about 4674.8720838115. The cubic root of 21854429 is about 279.5845411677.

The spelling of 21854429 in words is "twenty-one million, eight hundred fifty-four thousand, four hundred twenty-nine".