21470380 has 24 divisors (see below), whose sum is σ = 47461680. Its totient is φ = 8136000.

The previous prime is 21470377. The next prime is 21470381. The reversal of 21470380 is 8307412.

It is not an unprimeable number, because it can be changed into a prime (21470381) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 27871 + ... + 28630.

It is an arithmetic number, because the mean of its divisors is an integer number (1977570).

Almost surely, 2^21470380 is an apocalyptic number.

21470380 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21470380 is an abundant number, since it is smaller than the sum of its proper divisors (25991300).

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

21470380 is a wasteful number, since it uses less digits than its factorization.

21470380 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 56529 (or 56527 counting only the distinct ones).

The product of its (nonzero) digits is 1344, while the sum is 25.

The square root of 21470380 is about 4633.6141401718. The cubic root of 21470380 is about 277.9371353463.

Adding to 21470380 its reverse (8307412), we get a palindrome (29777792).

The spelling of 21470380 in words is "twenty-one million, four hundred seventy thousand, three hundred eighty".