21313005 has 16 divisors (see below), whose sum is σ = 38972544. Its totient is φ = 9743040.

The previous prime is 21313001. The next prime is 21313021. The reversal of 21313005 is 50031312.

It is a happy number.

It is not a de Polignac number, because 21313005 - 2² = 21313001 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21313001) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 101386 + ... + 101595.

It is an arithmetic number, because the mean of its divisors is an integer number (2435784).

Almost surely, 2^21313005 is an apocalyptic number.

It is an amenable number.

21313005 is a deficient number, since it is larger than the sum of its proper divisors (17659539).

21313005 is a wasteful number, since it uses less digits than its factorization.

21313005 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 202996.

The product of its (nonzero) digits is 90, while the sum is 15.

The square root of 21313005 is about 4616.6010223973. The cubic root of 21313005 is about 277.2563887500.

Adding to 21313005 its reverse (50031312), we get a palindrome (71344317).

The spelling of 21313005 in words is "twenty-one million, three hundred thirteen thousand, five".