21874328 has 32 divisors (see below), whose sum is σ = 47174400. Its totient is φ = 9314592.

The previous prime is 21874327. The next prime is 21874367. The reversal of 21874328 is 82347812.

It is a Cunningham number, because it is equal to 4677²-1.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21874327) 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, 8183 + ... + 10521.

It is an arithmetic number, because the mean of its divisors is an integer number (1474200).

Almost surely, 2^21874328 is an apocalyptic number.

21874328 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

21874328 is an abundant number, since it is smaller than the sum of its proper divisors (25300072).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21874328 is a wasteful number, since it uses less digits than its factorization.

21874328 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2519 (or 2515 counting only the distinct ones).

The product of its digits is 21504, while the sum is 35.

The square root of 21874328 is about 4676.9998930939. Note that the first 3 decimals coincide. The cubic root of 21874328 is about 279.6693716473.

The spelling of 21874328 in words is "twenty-one million, eight hundred seventy-four thousand, three hundred twenty-eight".