21493170 has 48 divisors (see below), whose sum is σ = 56339712. Its totient is φ = 5684640.

The previous prime is 21493159. The next prime is 21493193. The reversal of 21493170 is 7139412.

21493170 is a `hidden beast` number, since 2 + 1 + 493 + 170 = 666.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 10879 + ... + 12701.

It is an arithmetic number, because the mean of its divisors is an integer number (1173744).

Almost surely, 2^21493170 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21493170, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28169856).

21493170 is an abundant number, since it is smaller than the sum of its proper divisors (34846542).

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

21493170 is a wasteful number, since it uses less digits than its factorization.

21493170 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1967 (or 1964 counting only the distinct ones).

The product of its (nonzero) digits is 1512, while the sum is 27.

The square root of 21493170 is about 4636.0726914059. The cubic root of 21493170 is about 278.0354405070.

The spelling of 21493170 in words is "twenty-one million, four hundred ninety-three thousand, one hundred seventy".