21821074 has 8 divisors (see below), whose sum is σ = 35707248. Its totient is φ = 9918660.

The previous prime is 21821071. The next prime is 21821119. The reversal of 21821074 is 47012812.

It is a happy number.

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

It is a super-3 number, since 3×21821074³ (a number of 23 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (21821071) 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 3 ways as a sum of consecutive naturals, for example, 495912 + ... + 495955.

It is an arithmetic number, because the mean of its divisors is an integer number (4463406).

Almost surely, 2^21821074 is an apocalyptic number.

21821074 is a deficient number, since it is larger than the sum of its proper divisors (13886174).

21821074 is a wasteful number, since it uses less digits than its factorization.

21821074 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 991880.

The product of its (nonzero) digits is 896, while the sum is 25.

The square root of 21821074 is about 4671.3032442778. The cubic root of 21821074 is about 279.4422314827.

Adding to 21821074 its reverse (47012812), we get a palindrome (68833886).

The spelling of 21821074 in words is "twenty-one million, eight hundred twenty-one thousand, seventy-four".