21238380 has 36 divisors (see below), whose sum is σ = 64423632. Its totient is φ = 5663520.

The previous prime is 21238363. The next prime is 21238429. The reversal of 21238380 is 8383212.

It is a tau number, because it is divible by the number of its divisors (36).

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, 58816 + ... + 59175.

Almost surely, 2^21238380 is an apocalyptic number.

21238380 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21238380 is an abundant number, since it is smaller than the sum of its proper divisors (43185252).

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

21238380 is a wasteful number, since it uses less digits than its factorization.

21238380 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 118006 (or 118001 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 27.

The square root of 21238380 is about 4608.5116903400. The cubic root of 21238380 is about 276.9324167078.

The spelling of 21238380 in words is "twenty-one million, two hundred thirty-eight thousand, three hundred eighty".