21142928 has 40 divisors (see below), whose sum is σ = 42556800. Its totient is φ = 10168704.

The previous prime is 21142907. The next prime is 21142931. The reversal of 21142928 is 82924112.

It is a self number, because there is not a number n which added to its sum of digits gives 21142928.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 54158 + ... + 54546.

It is an arithmetic number, because the mean of its divisors is an integer number (1063920).

Almost surely, 2^21142928 is an apocalyptic number.

It is an amenable number.

21142928 is an abundant number, since it is smaller than the sum of its proper divisors (21413872).

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

21142928 is a wasteful number, since it uses less digits than its factorization.

21142928 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 519 (or 513 counting only the distinct ones).

The product of its digits is 2304, while the sum is 29.

The square root of 21142928 is about 4598.1439733875. The cubic root of 21142928 is about 276.5169196570.

The spelling of 21142928 in words is "twenty-one million, one hundred forty-two thousand, nine hundred twenty-eight".