21641316 has 24 divisors (see below), whose sum is σ = 50613024. Its totient is φ = 7197120.

The previous prime is 21641311. The next prime is 21641353. The reversal of 21641316 is 61314612.

It is a nude number because it is divisible by every one of its digits.

It is not an unprimeable number, because it can be changed into a prime (21641311) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4056 + ... + 7728.

It is an arithmetic number, because the mean of its divisors is an integer number (2108876).

Almost surely, 2^21641316 is an apocalyptic number.

It is an amenable number.

21641316 is an abundant number, since it is smaller than the sum of its proper divisors (28971708).

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

21641316 is a wasteful number, since it uses less digits than its factorization.

21641316 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4171 (or 4169 counting only the distinct ones).

The product of its digits is 864, while the sum is 24.

The square root of 21641316 is about 4652.0227858427. The cubic root of 21641316 is about 278.6727834813.

Adding to 21641316 its reverse (61314612), we get a palindrome (82955928).

The spelling of 21641316 in words is "twenty-one million, six hundred forty-one thousand, three hundred sixteen".