21445234 has 8 divisors (see below), whose sum is σ = 32238720. Its totient is φ = 10698996.

The previous prime is 21445217. The next prime is 21445247. The reversal of 21445234 is 43254412.

It is a happy number.

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

It is a super-2 number, since 2×21445234² = 919796122629512, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21445199 and 21445208.

It is an unprimeable number.

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, 10654 + ... + 12505.

It is an arithmetic number, because the mean of its divisors is an integer number (4029840).

Almost surely, 2^21445234 is an apocalyptic number.

21445234 is a deficient number, since it is larger than the sum of its proper divisors (10793486).

21445234 is a wasteful number, since it uses less digits than its factorization.

21445234 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23624.

The product of its digits is 3840, while the sum is 25.

The square root of 21445234 is about 4630.8999125440. The cubic root of 21445234 is about 277.8285867710.

Adding to 21445234 its reverse (43254412), we get a palindrome (64699646).

The spelling of 21445234 in words is "twenty-one million, four hundred forty-five thousand, two hundred thirty-four".