21418210 has 48 divisors (see below), whose sum is σ = 43819776. Its totient is φ = 7524000.

The previous prime is 21418207. The next prime is 21418213. The reversal of 21418210 is 1281412.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21418207) and next prime (21418213).

It is not an unprimeable number, because it can be changed into a prime (21418213) 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 23 ways as a sum of consecutive naturals, for example, 37225 + ... + 37795.

It is an arithmetic number, because the mean of its divisors is an integer number (912912).

Almost surely, 2^21418210 is an apocalyptic number.

21418210 is an abundant number, since it is smaller than the sum of its proper divisors (22401566).

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

21418210 is a wasteful number, since it uses less digits than its factorization.

21418210 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 631 (or 620 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 19.

The square root of 21418210 is about 4627.9812013447. The cubic root of 21418210 is about 277.7118367328.

Adding to 21418210 its reverse (1281412), we get a palindrome (22699622).

The spelling of 21418210 in words is "twenty-one million, four hundred eighteen thousand, two hundred ten".