21376170 has 64 divisors (see below), whose sum is σ = 58423680. Its totient is φ = 5558400.

The previous prime is 21376163. The next prime is 21376171. The reversal of 21376170 is 7167312.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21376171) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 10105 + ... + 12035.

It is an arithmetic number, because the mean of its divisors is an integer number (912870).

Almost surely, 2^21376170 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21376170, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29211840).

21376170 is an abundant number, since it is smaller than the sum of its proper divisors (37047510).

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

21376170 is a wasteful number, since it uses less digits than its factorization.

21376170 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1988 (or 1982 counting only the distinct ones).

The product of its (nonzero) digits is 1764, while the sum is 27.

The square root of 21376170 is about 4623.4370332038. The cubic root of 21376170 is about 277.5300186664.

The spelling of 21376170 in words is "twenty-one million, three hundred seventy-six thousand, one hundred seventy".