21941928 has 48 divisors (see below), whose sum is σ = 61632480. Its totient is φ = 7313328.

The previous prime is 21941921. The next prime is 21941981. The reversal of 21941928 is 82914912.

21941928 is a `hidden beast` number, since 219 + 419 + 28 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a nude number because it is divisible by every one of its digits.

It is a junction number, because it is equal to n+sod(n) for n = 21941892 and 21941901.

It is not an unprimeable number, because it can be changed into a prime (21941921) 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 11 ways as a sum of consecutive naturals, for example, 3700 + ... + 7587.

It is an arithmetic number, because the mean of its divisors is an integer number (1284010).

Almost surely, 2^21941928 is an apocalyptic number.

It is an amenable number.

21941928 is an abundant number, since it is smaller than the sum of its proper divisors (39690552).

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

21941928 is a wasteful number, since it uses less digits than its factorization.

21941928 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11308 (or 11292 counting only the distinct ones).

The product of its digits is 10368, while the sum is 36.

The square root of 21941928 is about 4684.2211732582. The cubic root of 21941928 is about 279.9571703197.

The spelling of 21941928 in words is "twenty-one million, nine hundred forty-one thousand, nine hundred twenty-eight".