21375270 has 144 divisors (see below), whose sum is σ = 66903408. Its totient is φ = 4717440.

The previous prime is 21375253. The next prime is 21375293. The reversal of 21375270 is 7257312.

21375270 is a `hidden beast` number, since 2 + 137 + 527 + 0 = 666.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 163105 + ... + 163235.

It is an arithmetic number, because the mean of its divisors is an integer number (464607).

Almost surely, 2^21375270 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21375270, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33451704).

21375270 is an abundant number, since it is smaller than the sum of its proper divisors (45528138).

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

21375270 is a wasteful number, since it uses less digits than its factorization.

21375270 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 195 (or 185 counting only the distinct ones).

The product of its (nonzero) digits is 2940, while the sum is 27.

The square root of 21375270 is about 4623.3397019903. The cubic root of 21375270 is about 277.5261236668.

The spelling of 21375270 in words is "twenty-one million, three hundred seventy-five thousand, two hundred seventy".