21313672 has 16 divisors (see below), whose sum is σ = 40012560. Its totient is φ = 10643664.

The previous prime is 21313657. The next prime is 21313673. The reversal of 21313672 is 27631312.

It is a super-2 number, since 2×21313672² = 908545228247168, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21313673) 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, 10483 + ... + 12349.

It is an arithmetic number, because the mean of its divisors is an integer number (2500785).

Almost surely, 2^21313672 is an apocalyptic number.

It is an amenable number.

21313672 is a deficient number, since it is larger than the sum of its proper divisors (18698888).

21313672 is a wasteful number, since it uses less digits than its factorization.

21313672 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3300 (or 3296 counting only the distinct ones).

The product of its digits is 1512, while the sum is 25.

The square root of 21313672 is about 4616.6732611265. The cubic root of 21313672 is about 277.2592810073.

Adding to 21313672 its reverse (27631312), we get a palindrome (48944984).

The spelling of 21313672 in words is "twenty-one million, three hundred thirteen thousand, six hundred seventy-two".