21079170 has 128 divisors (see below), whose sum is σ = 67737600. Its totient is φ = 4556736.

The previous prime is 21079169. The next prime is 21079181. The reversal of 21079170 is 7197012.

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

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 35617 + ... + 36203.

It is an arithmetic number, because the mean of its divisors is an integer number (529200).

Almost surely, 2^21079170 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21079170, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33868800).

21079170 is an abundant number, since it is smaller than the sum of its proper divisors (46658430).

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

21079170 is a wasteful number, since it uses less digits than its factorization.

21079170 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 629 (or 623 counting only the distinct ones).

The product of its (nonzero) digits is 882, while the sum is 27.

The square root of 21079170 is about 4591.2057239902. The cubic root of 21079170 is about 276.2386876608.

The spelling of 21079170 in words is "twenty-one million, seventy-nine thousand, one hundred seventy".