21302928 has 30 divisors (see below), whose sum is σ = 59619014. Its totient is φ = 7100928.

The previous prime is 21302927. The next prime is 21302947. The reversal of 21302928 is 82920312.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 20358144 + 944784 = 4512^2 + 972^2 .

It is not an unprimeable number, because it can be changed into a prime (21302923) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 73825 + ... + 74112.

Almost surely, 2^21302928 is an apocalyptic number.

It is an amenable number.

21302928 is an abundant number, since it is smaller than the sum of its proper divisors (38316086).

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

21302928 is a wasteful number, since it uses less digits than its factorization.

21302928 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 147951 (or 147942 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 27.

The square root of 21302928 is about 4615.5095060026. The cubic root of 21302928 is about 277.2126853387.

The spelling of 21302928 in words is "twenty-one million, three hundred two thousand, nine hundred twenty-eight".