21170472 has 16 divisors (see below), whose sum is σ = 52926240. Its totient is φ = 7056816.

The previous prime is 21170453. The next prime is 21170507. The reversal of 21170472 is 27407112.

It is a Harshad number since it is a multiple of its sum of digits (24), and also a Moran number because the ratio is a prime number: 882103 = 21170472 / (2 + 1 + 1 + 7 + 0 + 4 + 7 + 2).

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 441028 + ... + 441075.

It is an arithmetic number, because the mean of its divisors is an integer number (3307890).

Almost surely, 2^21170472 is an apocalyptic number.

It is an amenable number.

21170472 is an abundant number, since it is smaller than the sum of its proper divisors (31755768).

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

21170472 is a wasteful number, since it uses less digits than its factorization.

21170472 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 882112 (or 882108 counting only the distinct ones).

The product of its (nonzero) digits is 784, while the sum is 24.

The square root of 21170472 is about 4601.1381200742. The cubic root of 21170472 is about 276.6369452436.

Adding to 21170472 its reverse (27407112), we get a palindrome (48577584).

The spelling of 21170472 in words is "twenty-one million, one hundred seventy thousand, four hundred seventy-two".