21282930 has 24 divisors (see below), whose sum is σ = 55335852. Its totient is φ = 5675424.

The previous prime is 21282923. The next prime is 21282953. The reversal of 21282930 is 3928212.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 21261321 + 21609 = 4611^2 + 147^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21282894 and 21282903.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 118149 + ... + 118328.

Almost surely, 2^21282930 is an apocalyptic number.

21282930 is an abundant number, since it is smaller than the sum of its proper divisors (34052922).

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

21282930 is a wasteful number, since it uses less digits than its factorization.

21282930 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 236490 (or 236487 counting only the distinct ones).

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

The square root of 21282930 is about 4613.3426059637. The cubic root of 21282930 is about 277.1259142480.

The spelling of 21282930 in words is "twenty-one million, two hundred eighty-two thousand, nine hundred thirty".