21187230 has 32 divisors (see below), whose sum is σ = 51093504. Its totient is φ = 5622816.

The previous prime is 21187217. The next prime is 21187241. The reversal of 21187230 is 3278112.

It is a self number, because there is not a number n which added to its sum of digits gives 21187230.

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, 5107 + ... + 8273.

It is an arithmetic number, because the mean of its divisors is an integer number (1596672).

Almost surely, 2^21187230 is an apocalyptic number.

21187230 is an abundant number, since it is smaller than the sum of its proper divisors (29906274).

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

21187230 is a wasteful number, since it uses less digits than its factorization.

21187230 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3400.

The product of its (nonzero) digits is 672, while the sum is 24.

The square root of 21187230 is about 4602.9588310129. The cubic root of 21187230 is about 276.7099188842.

The spelling of 21187230 in words is "twenty-one million, one hundred eighty-seven thousand, two hundred thirty".