21418156 has 12 divisors (see below), whose sum is σ = 37518768. Its totient is φ = 10698512.

The previous prime is 21418151. The next prime is 21418157. The reversal of 21418156 is 65181412.

It is not an unprimeable number, because it can be changed into a prime (21418151) 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 3 ways as a sum of consecutive naturals, for example, 3510 + ... + 7426.

It is an arithmetic number, because the mean of its divisors is an integer number (3126564).

Almost surely, 2^21418156 is an apocalyptic number.

It is an amenable number.

21418156 is a deficient number, since it is larger than the sum of its proper divisors (16100612).

21418156 is a wasteful number, since it uses less digits than its factorization.

21418156 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5288 (or 5286 counting only the distinct ones).

The product of its digits is 1920, while the sum is 28.

The square root of 21418156 is about 4627.9753672637. The cubic root of 21418156 is about 277.7116033418.

Adding to 21418156 its reverse (65181412), we get a palindrome (86599568).

The spelling of 21418156 in words is "twenty-one million, four hundred eighteen thousand, one hundred fifty-six".