21245028 has 36 divisors (see below), whose sum is σ = 57666672. Its totient is φ = 6069840.

The previous prime is 21245027. The next prime is 21245033. The reversal of 21245028 is 82054212.

It is a junction number, because it is equal to n+sod(n) for n = 21244989 and 21245007.

It is not an unprimeable number, because it can be changed into a prime (21245027) 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, 17478 + ... + 18653.

It is an arithmetic number, because the mean of its divisors is an integer number (1601852).

Almost surely, 2^21245028 is an apocalyptic number.

21245028 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

21245028 is an abundant number, since it is smaller than the sum of its proper divisors (36421644).

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

21245028 is a wasteful number, since it uses less digits than its factorization.

21245028 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36152 (or 36143 counting only the distinct ones).

The product of its (nonzero) digits is 1280, while the sum is 24.

The square root of 21245028 is about 4609.2329079794. The cubic root of 21245028 is about 276.9613086579.

The spelling of 21245028 in words is "twenty-one million, two hundred forty-five thousand, twenty-eight".