21216476 has 12 divisors (see below), whose sum is σ = 39313008. Its totient is φ = 9984192.

The previous prime is 21216469. The next prime is 21216479. The reversal of 21216476 is 67461212.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21216479) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 155936 + ... + 156071.

It is an arithmetic number, because the mean of its divisors is an integer number (3276084).

Almost surely, 2^21216476 is an apocalyptic number.

It is an amenable number.

21216476 is a deficient number, since it is larger than the sum of its proper divisors (18096532).

21216476 is a wasteful number, since it uses less digits than its factorization.

21216476 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 312028 (or 312026 counting only the distinct ones).

The product of its digits is 4032, while the sum is 29.

The square root of 21216476 is about 4606.1346050675. The cubic root of 21216476 is about 276.8371800937.

Adding to 21216476 its reverse (67461212), we get a palindrome (88677688).

The spelling of 21216476 in words is "twenty-one million, two hundred sixteen thousand, four hundred seventy-six".