21442845 has 8 divisors (see below), whose sum is σ = 34308576. Its totient is φ = 11436176.

The previous prime is 21442819. The next prime is 21442871. The reversal of 21442845 is 54824412.

It is an interprime number because it is at equal distance from previous prime (21442819) and next prime (21442871).

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 21442845 - 2⁷ = 21442717 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 714747 + ... + 714776.

It is an arithmetic number, because the mean of its divisors is an integer number (4288572).

Almost surely, 2^21442845 is an apocalyptic number.

It is an amenable number.

21442845 is a deficient number, since it is larger than the sum of its proper divisors (12865731).

21442845 is a wasteful number, since it uses less digits than its factorization.

21442845 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1429531.

The product of its digits is 10240, while the sum is 30.

The square root of 21442845 is about 4630.6419641341. The cubic root of 21442845 is about 277.8182696824.

The spelling of 21442845 in words is "twenty-one million, four hundred forty-two thousand, eight hundred forty-five".