21001470 has 64 divisors (see below), whose sum is σ = 58254336. Its totient is φ = 4746240.

The previous prime is 21001469. The next prime is 21001493. The reversal of 21001470 is 7410012.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 19855 + ... + 20885.

It is an arithmetic number, because the mean of its divisors is an integer number (910224).

Almost surely, 2^21001470 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21001470, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29127168).

21001470 is an abundant number, since it is smaller than the sum of its proper divisors (37252866).

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

21001470 is a wasteful number, since it uses less digits than its factorization.

21001470 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1145.

The product of its (nonzero) digits is 56, while the sum is 15.

The square root of 21001470 is about 4582.7360822984. The cubic root of 21001470 is about 275.8988549777.

Adding to 21001470 its reverse (7410012), we get a palindrome (28411482).

It can be divided in two parts, 2100 and 1470, that added together give a triangular number (3570 = T₈₄).

The spelling of 21001470 in words is "twenty-one million, one thousand, four hundred seventy".