21248380 has 48 divisors (see below), whose sum is σ = 46027296. Its totient is φ = 8236800.

The previous prime is 21248369. The next prime is 21248401. The reversal of 21248380 is 8384212.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 135262 + ... + 135418.

It is an arithmetic number, because the mean of its divisors is an integer number (958902).

Almost surely, 2^21248380 is an apocalyptic number.

21248380 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21248380 is an abundant number, since it is smaller than the sum of its proper divisors (24778916).

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

21248380 is a wasteful number, since it uses less digits than its factorization.

21248380 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 334 (or 332 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 28.

The square root of 21248380 is about 4609.5965116266. The cubic root of 21248380 is about 276.9758740342.

The spelling of 21248380 in words is "twenty-one million, two hundred forty-eight thousand, three hundred eighty".