21942828 has 36 divisors (see below), whose sum is σ = 57880368. Its totient is φ = 6996000.

The previous prime is 21942827. The next prime is 21942839. The reversal of 21942828 is 82824912.

It is a tau number, because it is divible by the number of its divisors (36).

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

It is a junction number, because it is equal to n+sod(n) for n = 21942792 and 21942801.

It is not an unprimeable number, because it can be changed into a prime (21942827) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 12423 + ... + 14078.

It is an arithmetic number, because the mean of its divisors is an integer number (1607788).

Almost surely, 2^21942828 is an apocalyptic number.

It is an amenable number.

21942828 is an abundant number, since it is smaller than the sum of its proper divisors (35937540).

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

21942828 is a wasteful number, since it uses less digits than its factorization.

21942828 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26534 (or 26529 counting only the distinct ones).

The product of its digits is 18432, while the sum is 36.

The square root of 21942828 is about 4684.3172394704. The cubic root of 21942828 is about 279.9609979689.

The spelling of 21942828 in words is "twenty-one million, nine hundred forty-two thousand, eight hundred twenty-eight".